Unfamiliar birds twittered in the tree-ferns, scouting for bugs. Small things scuttled in the brush. Fish swam in the water. There was plenty of life, but nothing to fear, yet.

 

      He lifted the last of the cases they had decided to move, brought it to his shoulder, and tromped through the sludge. Yes, they all had to be alert here, on guard against unknown menaces. But the air was wet and warm, the biting insects had not yet discovered him, and he felt marvelously free. Perhaps he would die tomorrow in the jaws of some monster whose name he could not pronounce - but he would die a man, not a sardine.

 

      Hex ranged ahead as they came out of the swamp and recovered firm footing. It was dusk, growing too dim for him to see clearly, but he liked the challenge. The manta drifted to one side and stopped beside a tree - a maidenhair, Aquilon called it, but it looked exactly like the ginkgo - and stood as a black blob. By tricks of vision - looking slantwise at specific objects, narrowing his eyes - Veg could still make out good detail. What was Hex looking at?

 

      He came up and peered. Was that a - ?

 

      It was.

 

      Veg squatted down beside the manta, holding up the teetering carton with one hand while he cleared away obstructing foliage with the other.

 

      It was the print, in hardening mud, of either a bipedal dinosaur or a very large bird. Three sturdy clawmarks, the points digging down and forward, no rear toe showing.

 

      Whether toothed or beaked, a land walker armed with effective talons that could gut a man in a hurry.

 

      The creature was somewhere within range of their camp. Veg was glad the mantas would be mounting guard this night.

 

      XI

 

      ORN

 

      The spoor was not fresh; only its protected location had preserved it. It could have been made a season ago, since the merest suggestion of odor remained. But it was sure, for his memory was strongest of all on such identification: a female of his species had roosted here.

 

      Did she remain in the valley? Was she still alive? Could he locate her? These questioas were vague and peripheral and largely beside the point. His mind grasped the fact that she existed, and his glands responded and ruled. The mating urge was upon him, no longer to be denied.

 

      Orn spent the night under the waterfall. It was uncomfortable and tiring, on top of his preceding labors, but the discovery of a trace of his own kind prevented him from leaving. He had to begin here and follow the trail until it became fresh. Convenience was unimportant. If there were another male - but there was not; the trace was that of an unbred bird. Such things were specific, in his line.

 

      In the morning he explored the neighboring terrain. She had been here; there had to be signs of her avenue of departure. He would discover them, however faint or fleeting.

 

      It was not easy, but he was geared for this. He would not be able to perceive so old a trail at all, were it of any other creature. But his pumping glands sharpened his senses, and all his memories focused on this one task. His search pattern identified another trace, downstream, and a third, and he was on his way.

 

      In two days he located fresher spoor, and in another day the roost she had used for a time. It was in the raised hollow of a rotting flat-leaf tree. Nose and eye and memory informed

him that she had departed when a predatory rep had scouted the region. She had lost some feathers, but not her life.

 

      She had fled into the mountain, perhaps as recently as Orn's meeting with the expanding sea on the other side of the continent This season, certainly. Here the trail became exceedingly difficult, for she had passed over shuddering, heated rock in her effort to shake the pursuit. But Orn widened his search pattern and persevered, as he had to, and in time picked up the spoor again where she had descended to the valley.

 

      Her prints and smell became mixed with those of many animals, as though she had frequented the haunts of a herd of Tricers. Again he had to cast a wider net, seeking a line of emergence, and again he succeeded, as he had to. Days old now, her trail stimulated him exquisitely. She was alone and nubile, and not very much older than he; she wanted a mate, but had found none. All this he read in her spoor, knowing the signals from millennia past, and his desire for her became savage.

 

      But he did not find her. She found him.-

 

      She had come upon his own trail, in her roundabout rovings, and recognized it immediately. In less than a day she had caught up.

 

      Orn looked up from the newly hatched brach he was feeding on, suddenly aware of her presence. Across the open space of the deserted Tricer stamping ground they peered at one another. His beak was smeared with the blood of the fleet young rep, his nose suffused with the fresh odors of its open-carcass, and in this delicious and romantic moment he viewed the bird who was to be his mate.

 

      Ornette: she was shorter than he by the width of one dry tail feather. Her beak was slender, a delicate brown matching the scales of her muscular thighs. Her eyes were large and round, half shuttered by the gray nictitating membranes. The white neck feathers were sleek and bright, merging gracefully into the gray breast area. Her body plumage fluffed out slightly, lighter on the underside, for she had been moving through high brush. Her wings were well kept and handsome, looking larger than they were because of the unusual, almost regressive length of their primaries. Her tail, too, had sizable retrices, and the coverts displayed the grandeur of the nuptial plumage. Even the claws of her feet glistened with natural oil. from her drifted the perfume of the distaff, at once exciting and maddening to the male. She was beautiful and wholly desirable.

 

      Then she was away, whirling her shapely sternum about and running from him; and he was running after her with all his strength, his meal forgotten. She disappeared into high palmetto brush, outdistancing him; but it was a chase he was certain to win, for his thews were heavier, his masculine endurance greater. This was the way it was meant to be, and had been, throughout the existence of the species.

 

      She fled toward the swamp, passing into the territory of the Struth, that zealous rep so like Orn himself. That surely meant trouble, but there was nothing Orn could do about it. If he tried to circle to head her off, he would only lose distance, for she was for the moment as fleet as he.

 

      She dodged around a giant fir, sending green sprigs flying, and sheered away before encountering the Struth. She knew! She bore north, much to his relief, though that was territory he had not scouted. Her pace slowed as the ground became marshy - but so did his own. It would be a long time before he caught her, this way. This, too, was as nature had decreed.

 

      She ran north for a time, then veered west, toward the mountains. Soon they were ascending, leaving the steamy valley below. Flying aves scattered from their path and grazing young reps scooted away. A wounded adult Tricer, come this far to die, looked up startled. Through increasingly leafy trees they went, where mams twittered in the branches, and on into the grassy elevation where arths swarmed in sunlight, but Ornette did not slacken her pace, running up until the air became cool; on until the snows began. But Orn did not feel the cold. Slowly he gained on her.

 

      She changed course at last, running north along the fringe of white while the sun dropped toward the mountain crest. Then down again, into the valley, into the thickest greenery, spreading her wings to aid control in the precipitous descent. She gained on him again, utilizing those longer feathers, but on the level bottom where the reps roamed he got it back. And up again, almost to the snow, and still Orn gained on her, though he had never run so long without resting.

 

      The second time they came down at the northern apex of the great valley, beyond the swamp. Here there was a higher plain, too dry and cold for the comfort of most reps though the little mams were plentiful. And here, abruptly, the light of the sun was cut off by the mountain range. It was early dusk, Ornette stopped, panting. Om, hardly two wingspans behind, stopped also. The chase had to halt when the sun dropped, to resume in place when it rose again. The night was for feeding and resting and ... courtship. Thousands of generations before them had determined this, and the pattern was not to be broken now.

 

      The swamp spread out below from a comparatively tiny tributary stream here, and there were fish in it and mams in burrows adjacent and arths available for the scratching. They hunted separately, and fed separately. Then, as full darkness overtook them, they began the dance.

 

      Ornette crossed the plain, away from him, until she was a female silence in the distance. Orn stood, beak elevated, waiting. There was a period of stillness.

 

      Then Orn stepped forward, spreading his wings and holding them there to catch the gentle evening breeze. He gave one piercing, lust-charged call. She answered, demurely; then silence.

 

      Orn moved toward her, and she toward him, each watching, listening, sniffing for the other. Slowly they came together, until he saw the white of her spread wings. The remiges, the rowing feathers, were slightly phosphorescent when exposed in this fashion, slick with the oils of courtship exercise; and so she was a winged outline, lovely. He, too, to her.

 

      In the sight of each other, they strutted, he with the male gait, she the female. They approached, circled, retreated, their feet striking the ground in unison, wings always spread. Then Orn faced her and closed his wings, becoming invisible, and she performed her solo dance.

 

      Wings open; wings closed. On and off she flashed, a diffuse firefly, her feet beating the intricate courtship meter, now steady, now irregular, always compelling. Far back into her ancestry the females had done this series for waiting males, taunting them with the nuptial ritual.

 

      Then her dance halted, and the plain was quiet again. Orn's turn. He spread, commenced the beat, closed, whirled, jumped, spread, and instinct carried him on irreversibly. Tap-tap-tap against the turf, the flapping of wings measured by that cadence but not matching it. A faster, fiercer dance than hers, domineering, forceful, signifying what male expression in any species signified, but artistically, and not without gentle undertones. Forward, back, around; one wing flashing, then the other, as though he were jumping back and forth. But silent, except for the feet; a pulsing ghost. Finally an accelerated beat, wings and feet together, climbing as though into takeoff - and silence. The dance was done. Orn rested, alone in the dark, letting his heart subside. It had been a good effort, following a good chase - but better things awaited the morning. He made his way to the roost he had selected while foraging. Ornette, out of his sight as the ritual dictated, did the same.

 

      A quick meal at daybreak. Then, as the sun struggled over the eastern pass, the chase resumed. She was fresh again, recovering better than he, and she was familiar with this terrain, and he lost ground. Up the face of the northern range, across a low, hidden pass leading into another rich valley - but she turned back into their own, south. Even to the verge of the swamp she ran, passing briars, moss, and fungus that wrenched feathers from him or powdered him with spores as he charged carelessly through. At one point she intersected the spoor of a giant rep predator, and reversed her field hurriedly. It would not do to have trouble of that nature on this romantic occasion!

 

      Up to the snows again, across a hot stream that melted its own channel through ice, down ... and before noon Orn was gaining on her again. She was tired; her feathers no longer glistened sleekly, her beak was no longer held high. She made to ascend once more, but he shortened the distance between them so rapidly that she desisted, staying on the contour. They were near the southeast corner of the valley now, separated from his original entry by swamp and bay.

 

      Orn approached within a wingspan, no longer straining. She was so worn he could keep the pace easily; his season's travel had conditioned him for this, and he had recovered his strength during his days in the valley. And - he was male. But the time to catch her was not quite yet, and he dallied.

 

      Aware of her defeat, Ornette stumbled and hardly caught herself in time. In desperation she waded out into the shallow water of the bay, toward a nearby island, but she was so gaunt and tired that this was even worse, and she had to turn back.

 

      Orn was waiting for her, victorious. As she climbed slowly to the bank he pounced on her and buried his beak amid the tender down feathers of her neck, but did not bite. She hardly resisted; she had been conquered. She dropped to the ground and lay there at his mercy.

 

      Orn shook her once, not hard, and let her go. He trotted to a nearby bed of moss. He gathered a succulent beakful and brought it to her as a counteroffering. She sniffed it weakly, looked at him through the nictitating lid, and accepted. With these first tokens of submission and of the nest they were to build and share, their courtship was done. They had found each other fitting; soon they would mate and settle, uniting their memories in their offspring.

 

      Another morning - the first of their new life. They scouted the vicinity and decided to cross to the island Ornette had not been able to reach before. This was thickly wooded with firs, and seemed to represent a suitable haven from most carnivores. The big land walkers would have difficulty crossing to it, while the sea dwellers would be unlikely to venture among trees of such size, even if they were able to leave the water.

 

      The two waded in and paddled with their abbreviated wings, entering the water while the chill remained in the air. The sea itself was warm, and they would be vulnerable to submerged

predators. But the reps of the surface or shore would still be torpid, and so less dangerous than usual. Morning was the best time to forage when such creatures were near. Not a ripple disturbed the sea, apart from those of their own motions. They crossed quickly and safely - but this was not a risk they would take again soon.

 

      The island ground was spongy but not soggy; the matted fir droppings made an excellent fundament. Though the island was small, it was not flat. The trees ascended a mound in the center. Orn perceived it for what it was: the tip of a submerged mountain. Once it might have stood as tall and cold as the peaks of the ranges enclosing this warm valley, but its understratum had given way and allowed the bay to encroach. Its original formation had been volcanically inspired. None of that animation remained to it now, or Orn would not have stayed.

 

      Near the water were thick stands of club moss, the tops of the plants as high as his head. Once this species had been a giant many times that height, but somehow it had diminished to this innocuous status, and was still shrinking elsewhere on the continent. Horsetail rushes were also abundant, though similarly restricted in size.

 

      At the fringe of a twisting inlet they discovered the ideal nesting site: a mossy peninsula sheltered within a northern baylet. It was protected from the harsher waves of the ocean, and from the openness of the main island. The bridge to the site was narrow, so that a single bird could defend it, and the bay itself was deep enough to discourage wading. Yet the mouth of the inlet was toothed by jagged rocks, preventing access by most large sea creatures. A stand of several pine served as a breaker against offshore wind, and the main body of the island guarded against the sea wind. The soil was rich with grubs, and small fish teemed in the inlet, and clams in th gravel below it.

 

      Ornette was pleased, already casting about for the specific spot for the nest. But Orn was more cautious. The experience of his ancestry told him that seemingly ideal locations generally appealed to more than one individual or species. Sometimes a flawed site was actually superior, because of this competitive factor. And he was directly aware of the fate of his parents, who had nested on another apparently ideal island. Orn did not want his own chicks to be orphaned as they hatched.

 

      The smell of rep was strong here, and there were many droppings. Something used this peninsula regularly but he was unable to identify the particular creature before actually  seeing it.

 

      Ornette, female, had few such compunctions. Defense of the nest was not her primary responsibility; filling it was. She scratched the earth in several areas and fluttered for his attention. This spot? This? Or nearer the water?

 

      Unable to subdue her enthusiasm without unreasonable gruffness, Orn approved a site beside the inlet. This was atop a large elevated stone, concave above, that he deemed secure from both flood tide and the intrusion of egg-sucking reps and landbound arths. A wingspan across and half that high, it was large enough for a proper nest yet had a sharply defined perimeter. The eggs would be as safe there as anywhere in the open, and of course they would never be left unattended.

 

      If only he knew what manner of rep frequented this locale. It might be innocuous.

 

      All afternoon they worked on the nest, foraging amid the pines for needles and cones, and fetching moss for spongy lining. Ornette wove the long stems of shore plants into a great circular pattern and calked the interstices with the clay Orn scooped up from beneath the water. The nest would have to bake for a day in the sun before the padding was installed, and if it rained they would have to repeat the calking and wait again. Orn hoped that such delay would not happen. The nest had to be complete before mating occurred.

 

      As the sun touched the bright crest of the mountain wall, shapes appeared in the sky. They were the huge gliding forms of the ptera, largest of the flying reps. Orn recognized the creature now, as the visual trigger activated his memory. The trees, the droppings, the odor - this was a nesting site for the enormous gliders.

 

      The shapes came in, drifting on the rising currents in the atmosphere but steadily approaching the island. Orn stood in the center of the peninsula beside the stoutest tree and made ready for the confrontation that had to come. Ptera generally did not get along well with true birds.

 

      Three spiraled toward him. Their wings were monstrous: four times Orn's own span. Their heads were large, with long toothless beaks and crests of bone that extended back as a counterbalance. A flap of skin stretched from the crest back above the body, serving as a rudder that oriented each creature into the wind. Their bodies had neither hair nor feathers, but scales as fragile as natal down and hardly more protective.

 

      Orn continued to watch, remembering more. The ptera, like the other larger flyers among the reps, had tiny legs to which the rear of the wings attached. The tail was so small as be useless. The forelimbs that braced the wings were many times the size of the hind limbs, and the fourth phalange extended half the length of each wing. Ptera, able to glide all day without respite, could not walk on land. There was nothing to fear from this particular species; any individual who tried to attack him in the air would be at a severe disadvantage because Orn could knock it down and kill it while it flopped helplessly on the ground. A ptera could not fly from ground level.

 

      Orn dropped his fighting stance, though he kept close watch on the visitors. One could never be certain what a rep would do, though the ptera were not notably foolish.

 

      The three circled overhead, then evidently decided that he was not a threat and swooped at one of the pines leaning over the water. Each passed over a horizontal branch high on the trunk, let down its little legs, caught hold with marvelous accuracy and spun around.

 

      Then the wings folded and they hung inverted, three suddenly smaller bodies wrapped in folded leather, the downy scales outward. They were well beyond Orn's reach and he,

effectively, was beyond theirs. Friends the two species not, but coexistence was feasible.

 

      The mystery of the rep inhabitant had been alleviated. The three ptera combined would mass no more than Orn alone, for they were insubstantial things despite their monstrous wingspan. And if they nighted safely here, so could he.

 

      Ornette was unconcernedly scooping small fish from the water. She had known it all along.

 

      They fed together and slept that night beside the half-constructed nest, the head of each tucked under the wing of the other, sharing warmth and love. It rained, forcing them to scramble to shelter the nest with their spread wings, but it was a good night.

 

      The ptera were not early risers. Long after the birds had foraged for their morning meal, the three reps hung from their branches tightly cloaked. Only when the sun itself touched their bodies did they move, and then stiffly. The scant chill of this valley night was enough to incapacitate these creatures who lacked internal control of their body temperatures. Even the hairy mams were better off than that.

 

      The nest was baking. For the present, the birds had nothing constructive to do, so they explored the peninsula thoroughly, searching out the best fishing area and the richest infestations of edible arths - and watched the reps.

 

      The three began to stir more actively as the sunlight heated them. Their heads rotated and the small claws at the break of their wings flexed. They began to flutter gently, opening their membranes to the warmth. Those tremendous wings could trap a large expanse of sunlight, heating the entire system.

 

      Then, one by one, the reps dropped. The first fell almost to the water before leveling out, then swooped perilously close to the surface. Its wings stretched out so thinly that the sunlight made them translucent, the veins showing dark like the web-work of deciduous leaves. The ptera flapped clumsily, its very bones bending in the desperate effort to gain altitude, and Orn felt a surge of longing. Once his own line had flown, and takeoff had resembled this. He knew the rep had to reach an updraft quickly, for its reserve of energy was small and a descent into the cool water would be fatal.

 

      It found a favorable air current and fought its way to a safe height. The second ptera dropped, following a similar course. But the third, the largest, did not. The wind had shifted, and that particular corridor to the sky was closed. Anxiously it maneuvered from side to side, but remained too low. The tip of one wing as it banked touched a wave, jerking the creature about. It righted itself, but now was too low even to flap without disaster.

 

      The drama was not over. Carefully the ptera circled, coasting closer and closer to destruction but never quite touching the sea. It came in toward the island, toward Orn's nest.

 

      Alarmed, Orn ran to protect their property. But the ptera was only trying to reach land before falling that last bit. It did not succeed. With a sick splash it struck the water, so close to the nest that Orn spread his wings quickly to intercept the flying droplets before they wet the clay and forced the postponement of his nuptial.

 

      The ptera had reached the shallows, however, swimming ineffectively but determinedly, and was able to struggle the small remaining distance to the shore. Dripping and bedraggled, it climbed to land and lay there for a moment, watching Orn.

 

      The creature was exhausted, cold and helpless now; it would be easy to kill. It had very nearly killed itself, bouncing over the rocky barrier to the inlet. But Orn, imbued with the romance of his newly completed courtship and sympathetic to a certain extent to the rep's plight, did not attack. Anyway, there was very little good meat on it, and he was not hungry at the moment. Had such a creature fallen near him as he struggled through the desert, it would have been a different matter.

 

      After a while the ptera pulled itself away from the bank, scraping along on bedraggled, wet, folded wings and weak legs. It was unable to stand or walk, but it could crawl. It seemed surprised that no attack had come, but was not remaining to contemplate the matter. Indeed, Orn was not certain he had done the right thing; it went against his nature.

 

      The ptera scrambled awkwardly to its tree, then hooked its wing claws into the bark. Laboriously it climbed, clinging to the trunk with its wings draped down from the bend, a dripping cape. Only when it reached its branch did it rest again, flopped halfway over the wood with its long heavy head hanging in fatigue.

 

      At last it assumed the sleeping position, but did not sleep. It walked out from the trunk, sidestepping upside down, until it had good clearance. It spread its wings so that the sun caught them and warmed them and made it entirely dry. Then dropped again.

 

      This time it completed the maneuver successfully, and disappeared proudly into the sky.

 

      That day they watched the pteras feeding by swooping low over the waves and scooping small fish into their long bills. Because they did this at high speed and always facing the wind, they were able to touch the water and recover elevation without being immersed and trapped, and the massive rearward bones of their heads balanced the weight of the solid morsels they lifted. It was a graceful operation.

 

      Orn hardly cared about the life and fate of any given rep, yet in some fashion his act of mercy enhanced his relationship with Ornette. Together they gathered the last of the supplies they required. All day the sun shone without remittance - unusual, for this valley - and by late afternoon they decided the clay was firm enough. They packed in the lining layers and made the nest smooth and comfortable.

 

      That night they occupied their nest for the first time, snuggled pleasantly together within its bowl. And Ornette presented, and they mated at last, while the three ptera hung silent.

 

      XII

 

      AQUILON

 

      She had slept in close proximity to these two men before, both on the planet Nacre and the raft Nacre. She knew them well and loved them both. But now she felt an increasing discomfort, a sense of impropriety. She had almost decided to leave them rather than continue to come between them, back when they had orbited Earth in the quarantine capsule. Events had prevented that, but did not really dispel the mood that had precipitated the decision. For surely she would come between them, and be the cause of sorrow and misfortune, if she remained a member of the party. She felt the female urges within her, compelling her to -

She peered at the roof of the lean-to, invisible in the darkness but present in her mind's eye, for she had spent hours plaiting it. Yes, she felt compelled - but to what'?

 

      To choose.

 

      Aquilon was a woman. She had breasts and they were not simply for appearances; she had thighs and not entirely for walking. She was long past adolescence. But she had not felt the need of the physical male until - that agent Subble had aroused her, somehow, back in her tight Earth apartment, and turned her down. She had never realized before that a man could do that to her, and it had been a shock. When she had had no smile to show the world, she had bypassed social life, of course; but that new smile had seemed to open all the world to her, to lay waste all prior mysteries. Subble had routed that euphoria.

 

      She had not loved him, those few hours they conversed, but she had felt his controlled masculinity tangibly. He had made her realize that the love she professed for Veg and Cal was an intellectual thing possessing no physical substance; a sympathetic resonance of the love they professed for her. She had never actually imagined herself undertaking a sexual relation with either.

 

      Subble had been an agent, in more senses than one. He could move with seemingly irresistible speed and force and accuracy, yet hold a difficult pose indefinitely without sagging. He could talk philosophy and he could kill without compunction. He was handsome, yet ruthless even in his kindnesses. He was a body like Veg's, a mind like Gal's. He had understood her.

 

      Subble had died, making any consummation with him, however theoretical, a waste of emotional effort. Of course there were hundreds, perhaps thousands, of agents virtually identical to him, and, designed to be exactly that, computerized. But it had not been the assembly-line physique and mind that made the connection between him and her; it had been their mutual experience. The Subble was gone forever; the close resemblance of other agents was irrelevant.

 

      That threw her back into the trio - with a difference. It had taken her this long to realize it.

 

      But what to do about it?

 

      She fell asleep without an answer. Her dreams, however, were not of love; they were of Brachiosaunis.

 

 

      The explorations of the next week banished any doubt they might have entertained about the nature of this region. They had struck paleontologic gold. This was a thorough Cretaceous enclave in the Paleocene world. The full spectrum of the golden age of reptiles was present - a vast pyramid of ecology, with inordinately plentiful small forms, largely mammalian, and lesser numbers of larger, dominant reptiles. Here, in fact, there were dinosaurs.

 

      Ten miles up the shore, northwest from their camp ('There's nothing so permanent as a temporary camp,' Cal remarked, and smiled for some obscure reason), the ocean inlet became the delta of a southbound river. It was evident that the towering mountain chain had once enclosed a salt-water bay some forty miles across and sixty miles long, but almost all of it had been filled in by the rich silt and debris of the river to form a tremendous warm swamp. Its center was a freshwater lake, swollen daily by ungentle rain, overgrown by soft vegetation, while its fringe rose up into the foothills of the giants. All of it was tropically warm, near sea level, the nights dropping down to a temperature of about 65° F., the days rising to 85° F., with the predominating level toward the higher end of that scale.

 

      In the direct sun it was much hotter, of course. At midday hardly a reptile moved. They were all hiding in whatever shade was available, predator and prey together. Aquilon had forgotten how much reptiles liked to rest.

 

      The corner of the delta nearest them was the sporting place of several families of duckbill dinosaurs. Cal insisted on using the proper classification terms - the 'family' being ranked below 'order' and above 'genus' - and of course the reptiles did not have families in the social sense. But they did associate in small or large groups, except for the carnivores, and Aquilon preferred to anthropomorphize to that extent.

 

      In the liquid portion of the swamp a lone Brachiosaurus browsed, perhaps the same one they had encountered so awkwardly upon their arrival. It consumed anything soft that grew within range of its neck, and once she saw it scoop up a fair-sized rock. Cal had abated her astonishment: it developed that such reptiles normally swallowed rocks to aid in their digestion of sturdier morsels. Long periods of stasis were required while the voluminous and tough material being processed was crushed and gradually assimilated; this was one reason, he

explained, why mammals and birds were far more mobile than reptiles on a twenty-four-hour basis. Superior digestion eliminated that torpor. She decided that she'd feel torpid too if she had to let rocks roll around in her stomach.

 

      Sometimes the sauropod disappeared entirely, and she presumed it was taking a nap under the surface. It was an air breather, but probably it could hold its breath for a long time without particular discomfort, much as a whale did - or would do, tens of millions of years hence.

 

      Across the bay near the eastern mountains were more duckbills, these ones grotesquely crested; she meant to have a closer look at them in due course. And in the plainlike reaches between slush and mountain, where fern trees and cycads were particularly lush, were herds of Triceratops, plus scattered Atikylosauruses, both armored reptiles of considerable mass. Truly, it was a paradise of paleontology.

 

      And Cal, the paleontologist, was becoming more and more depressed. She found this hard to understand. Cal had a pessimistic view of life, but there was always sound reason behind his attitudes. If only he would explain what was bothering him!

 

      Meanwhile, she drew a map and filled in all the details observed and conjectured to date. She put in the volcanic mountains, and Scylla and Charybdis, and their camping place. She marked a dotted line to show their route of entry. Perhaps this could serve as an adjunct to Cal's eventual report.

 

      They found a better location about twenty-five miles north and made a second, more permanent camp beside a streamlet coursing down from the western range. She updated her map accordingly. There was a pleasant waterfall nearby, and hilly ground that seemed to be secure from the plains-dwelling armored dinosaurs, and the air was cooler here. She liked it very well. Veg, exploring indefatigably, said there was a snowy pass through the range at the head of the stream, and some hot areas of ground: even the silent volcanoes were far from defunct.

There was danger here, certainly; there were savage predators larger than any existing on Earth before or after, though she had seen only their tracks so far. But danger was not objectionable per se, so long as one did not push one's luck. This was a visit in history, in historical geology, an experience like none possible to any home-bound person. So very like Earth...-

 

      Like Earth? It was Earth, according to Cal, though he hadn't spoken on that topic in the past month. She kept forgetting that. Perhaps it was because she thought of Paleo as a world in its own right; or maybe she simply could not assimilate the notion that something she might do here could change her own world, perhaps even eliminate the human species and extinguish her too. Then she could not come here, because she didn't exist, so no change would be made after all...

 

      No, it made no sense, and this was Paleo, and she refused to be ruled by fears of paradox.

 

      But there were mundane problems. The insects were fierce, after they had zeroed in on the new arrivals, and all three of the humans, and for all she knew the mantas too, had welts from nocturnal bites. Someone had to keep watch part of the night, because they had agreed that it wasn't fair to make the mantas assume the whole task. That meant that one of the three was generally short of sleep and temper. It was surprising how quickly a nagging itch and insufficient rest could flare into personal unpleasantness. And the food -

 

      Her hands were raw and her nails cracked from scraping in the dirt for edible tubers. Veg ate no meat at all, and she had stopped doing it the past few months, but now the thought of roasted fish was tempting indeed. Coconut was fine, and so were the few small berries growing on the mountainside, and she had pounded nutlike fruits down into powder for something vaguely like bread, baking it laboriously over the kerosene burner. But the lush greenery of the waterside was tough and stringy and internally gritty even when thoroughly cooked, and tasted of creosote. It made her appreciate why Brach needed rocks in his belly to grind it up; he couldn't stand to keep it in his mouth long enough to chew it! The Tricers didn't bother; she had seen them biting off entire fem trees, and chewing up the trunks, their beaks and phenomenal back teeth like sawmills. Cal had explained that too: the Tricers had multiple rows of teeth set one on top of the other, the worn ones being replaced automatically with new. And the upper jaw did not meet the lower directly; the teeth slid past each other in a sheering action controlled by jaw muscles a yard long. To think that some researchers had theorized that the dinosaurs died out because they could not chew the flowering plants!

 

      For the supposedly superior dentition of the human beings, the softer tubers were better - but some made her sick, and she could not be sure, yet, which. The effect seemed to be delayed and inconsistent. Cal did eat fish, and also cooked fat lizards without compunction, and had no trouble. By unspoken agreement he did it alone; none of them were sure to what extent their dietary differences were ideological or physical, but no one criticized another in this one area, even when tempers were shortest.

 

      She saw it coming: in time she would change over again. On Earth she had been appalled at the way animals were raised in cruel captivity for slaughter, but here the animals were wild and free and able to look out for themselves, and it was the natural order that the weak or slow or stupid became food for the strong and swift and clever.

 

      But mainly she was hungry, and her tastes were falling into line. What held her back was the fear that the moment she reneged on vegetarianism, Veg would turn from her, and thus she would have made her choice of men involuntarily. Perhaps Cal, with his brilliant mind and strength of will, would be the one anyway - but she wanted to make the decision freely, not via her intestines.

 

      Meanwhile, too, there was considerable drudgery in paradise.

 

      She broke from her task - picking over a basket of objects resembling beechnuts Veg had gathered from somewhere, to eliminate the green or rotten or wormy ones (about half the total!) - and picked up her sketch pad. At least she still had that: her painting. She headed downriver, in the direction of chopping noises.

 

      Veg was hacking down selected hardwood saplings, comparatively rare in this valley, and skinning them. He had a row lying nude in the sun, each about six feet long and one to two inches in diameter, depending on the end. He was using his hefty scout knife, rather than attempting to harvest the slender trees by axe, and his large arm muscles bunched handsomely as he worked.

 

      Yes, she thought, he was a powerful man, if not really a handsome one. Hardly the kind she would have taken for a vegetarian, a hater of killing. A strong, strange man, for all his simplicity.

 

      'What are you making?' she inquired at last.

 

      'Quarterstaffs,' he grunted.

 

      'Quarterstaff? Isn't that a weapon?'

 

      'Yeah. We lost our steam rifle in the turnover, and there are animals here even that wouldn't faze. Got to have something. Staffs are defensive, but effective.'

 

      'But a weapon -'

 

      'Defensive, I said!' Last night had been his turn on watch, the human half, and he had whistled cheerfully. But now he was feeling it. She knew what four hours of sleep felt like, but still didn't appreciate his tone.

 

      She kept her voice level. 'You mean against a dinosaur?'

 

      'I figure you could jam it down his throat, or maybe stop his jaws from closing on you, or just bop him on the nose. Lot better'n bare hands.'

 

      She eyed the slender poles dubiously. 'I wouldn't care to try it on Triceratops. He'd bite it right -'

 

      'Nobody's making you!' he snapped.

 

      Affronted, she walked away. She was disgusted with herself for reacting emotionally, but she was angry at him too. He didn't have to yell.

 

      She found Cal farther downhill, north of camp, observing a small tame dinosaur. She had seen quite a number of these innocuous, almost friendly little reptiles about, for they usually grazed in herds of a dozen or more. This one was about five feet tall with a head of considerable volume compared to the average species of reptile. Brightly colored tissue surrounded its face, red and green and yellow; it circled all the way around its head and rose above in a spongy dome. Aquilon had no idea what such a display did for its possessor, but remembered that evolution always had realistic purpose.

 

      The creature was nibbling bracken, and though it looked up as she approached, it returned to its meal when she halted. Harmless, certainly; had it been a predator, it would have attacked or retreated Immediately. Aside from that she could tell by its tooth structure that it was herbivorous.

 

      She came to stand behind Cal, knowing the sound of her voice would spook the beast. She opened her sketch pad and painted the dinosaur's portrait, not one to miss the opportunity. Her paper, fortunately, had been salvaged from the raft wreck, though each page was discolored around the rim. Perhaps it was not as valuable materially as the radio equipment, but she was much happier to have it.

 

      She was intrigued by this reptile. It looked defenseless, and its head was so large and tali! Did it have a brain capacity rivaling that of man? Could it be intelligent, in human terms?

 

      Its actions suggested nothing of the kind, but-

 

      When she finished, Cal handed her a sheet of his notes. Usually he employed the voicetyper, but this time he had been doing it by hand, to preserve silence. She looked at the crude writing: 'TROODON, "bonehead" ornithischian. Solid bone skull, small brain.'

 

      Solid bone! That skull she had thought to contain a massive brain ... What a waste of space!

 

      There was more, but she looked up to see one of the mantas approaching. The little dinosaur took alarm and bounded away like a huge rabbit, keeping its head erect.

 

      'Why all bone?' she demanded, free to speak now. 'Doesn't it just slow it up, when there is danger?'

 

      That has bothered paleontologists for some time,' Cal admitted. 'I'd very much like to see Troodon in a situation of hazard, and make notes. At present I can only conjecture. A large carnosaur would ordinarily bite the head off one that size, as the best way to kill the creature rapidly. The body would still cast about a bit, but the predator would be able to hold it down and feed on the carcass at leisure. But if it sank its teeth into Troodon's soft-seeming skull...'

 

      Aquilon laughed. 'No teeth! It wouldn't try that again!'

 

      'Not exactly. There are several inches of fleshy padding around the bone, that would cushion the impact. And the carnosaur would soon learn to take in the entire head, not part of it, and so succeed. But this would still be a respectable mouthful, perhaps quite tasty - yet unchewable. I think that by the time the meat were off the bone, the others in the herd would long since have taken advantage of the carnivore's preoccupation to get away. So it would be an indirect measure protecting the herd more than the individual.'

 

      'That's a grisly mechanism!'

 

      'Yet it would seem to limit herd liability, and perhaps discourage careless predators entirely. We do observe a thriving population of these species, at any rate.'

 

      The manta had arrived and settled into its lumplike posture. 'What is it, Circe?' she inquired, knowing that there would be valid reason for such an interruption. More and more, the mantas were keeping to themselves, associating only loosely with the human party. One always showed up for watch at night, and they certainly were not hiding; but they seemed to prefer their own company. Communications were adequate, she could understand Circe quite well now.

 

      STRANGE - IMPORTANT, the manta signaled with that combination of gesture and tail snaps they had gradually worked out as their code.

 

      'Dangerous?' She remembered how well Circe's warning had served the first time, when the tsunami came.

 

      NO. But the denial lacked full force, showing probability rather than certainty. THIS. And Circe snapped her tail in the dirt four times, leaving a mark like a footprint.

 

      'The bird!' Cal exclaimed. 'The bird that made those tremendous prints we saw at Camp One!'

 

      YES. TWO, Circe indicated.

 

      What's so distinctive about a large bird, here in the land of giants?' Aquilon asked Cal.

 

      'It may be our substantial evidence that this is a discrete world.'

 

      'Discreet? Oh, you mean "e-t-e" - discrete, separate?'

 

      'Alternate. A world parallel to our own in virtually every detail, but distinct. The concept is certainly more sensible than that of temporal displacement.'

 

      'Temporal - ? Time travel?, Changing the past? Paradox?' As though she hadn't worried about it too!

 

      'Something like that. The resemblance of Paleo to Earth is far too close to be coincidental. The size of it, the gravity, atmosphere, every matching species - but we've discussed this before. I've been assigning Earthly nomenclature because it fits, but I simply can not credit time travel. There has to be another explanation, and the alternate-worlds framework can be made to fit.

 

      'Back where we started from,' she murmured. 'But Earth didn't have dinosaurs during the Paleocene.'

 

      'We can't be sure of that, 'Quilon. This is an enclave, isolated, rather stringently from the rest of the continent. It could have happened on Earth, and have been entirely destroyed, so that no fossils remained as evidence - or merely be buried so deeply that we haven't discovered them yet. This location, particularly, would be subject to such an upheaval. I'll certainly check that out when ...' He paused, and she knew he was remembering their banishment. They could not return to Earth soon, if ever, even if they wanted to. 'It could have happened, and I rather think it did. The San Andreas Fault of our time is the landward extension of a Pacific ocean rift. The continent has overridden it, burying enormous amounts of undersea landscape. This valley could be part of that vanished structure, the mountains a reaction to the extreme turbulence of the area. There is nothing here inherently incompatible with what we know of our own world.'

 

      'I'm not sure I follow all that,' she said, wondering which of them he was straining to convince, and why the point was suddenly so important. 'But I gather that Paleo either is or is not Earth.'

 

      He smiled momentarily. 'That would seem to cover it. This could be Earth - except for that pair of birds Circe reports. Everything else fits, except the chronology of some of the

reptiles, such as the pteranodons. They should have become extinct before -'

 

      'But a big bird doesn't fit? I'd think that two birds would be easier to explain than a whole enclave of anachronistic dinosaurs.'

 

      'Not so. The enclave is merely a remaining pocket, a brief, geologically speaking, carryover. The bird - one of this nature, this early - would have had to evolve over the course of millions of years, and it would have ranged widely. There it would have been fossils, other evidences of its presence.'

 

      'Cal, that sounds thin to me. There are so many giant gaps in the fossil record -'

 

      'Quilon, we are faced with drastic alternatives. If this is Earth, we are faced with paradox. Paradox can't exist in practice; nature will resolve it somehow, and we might not like the manner of that resolution. Not at all. Principle of the monkey's paw.'

 

      'The what?'

 

      He didn't seem to hear her. 'But if this is not Earth, the implications are equivalently awkward. It is necessary to know.'

 

      'But it's ridiculous to claim that one bird - I mean two birds - that we haven't even seen - ' She stopped. She had just left an argument with Veg, and now was provoking one with Cal. Whatever the geological, ecological, paleontological, philosophical implications, their discussion would not affect the truth, and it was silly to let it prejudice their personal relations. Cal obviously had something more than a mere bird on his mind; that was a pretext to cover what he refused to discuss. Otherwise he would surely have seen his own illogic,

 

      It was her place to smooth things over, not to aggravate them. 'Let's go see!' she said.

 

      Cal nodded.

 

      They rejoined Veg, who seemed to be in better spirit now that his self-appointed task was done. Aquilon didn't mention their prior exchange.

 

      'How far?' was all Veg asked.

 

      Circe explained: twenty miles across the water.

 

      They used the raft, rather than make the dangerous trip around and through the unexplored swamp. They backtracked to Camp One, rebound the Nacre, and poled as far as the remaining day permitted.

 

      It was good to be afloat again, Aquilon thought, as she lay wedged between the two men in the cabin. Somehow, aboard the raft at anchor, decisions were not so urgent, and she appreciated the fact that the security of their position allowed all three to sleep at once. It would otherwise have been her night to stand guard...

 

      They had merely to pull together as a team of three, while the mantas relaxed, wherever it was that the four were spending this night. Let the theoretical questions settle themselves. Here it was nice.

 

      'Oh!' She jumped as a cold wash of water slid over the cabin floor, soaking her derriere. She had forgotten about that hazard. Tomorrow she would set about recalking the Nacre...

 

      Next day they beached the Nacre on the south shore of the small island Circe indicated and proceeded forward overland. They were quiet and cautious, so as hot to frighten the anticipated birds. Each carried one of Veg's new quarterstaffs, just in case.

 

      There was no excitement. The island was nothing more than the long-eroded peak of an ancient volcano, covered with firs and pines and surrounded by deep water. No large reptiles were in evidence, though there were some duckbill footprints. The human party crossed without event to the north side and discovered a tiny peninsula-and-inlet complex.

 

      A bird five feet tall stood guard at the neck of the peninsula. Veg marched at it, poking with the end of his quarterstaff. 'Shoo!' he said.

 

      The bird did not squawk and flutter away in the manner Veg evidently expected. It spread its wings, which were quite small for its size, and struck at the pole with its great curved beak. As Veg drew back, surprised, the bird raised one powerful leg high in the air.

 

      'Careful, Veg,' Cal called in a low tone. 'That's the one we're looking for, and it's dangerous. It's a predator - a killer. Look at that beak, those talons, those muscles. It could disembowel a man with one stroke of that foot.'

 

      Veg had come to the same conclusion. He brought the quarterstaff around sharply, striking the bird midway down its long neck. The bird fell back a pace, hurt.

 

      'Oh,' Aquilon exclaimed, putting her hand to her own neck. She didn't want the bird to be injured, particularly if it were as rare and significant as Cal intimated. It wasn't, of course; it could not be. But it was a remarkable specimen in its own right.

 

      She looked beyond it and spied the second bird, perched on a rock near the water. Worse and worse - that would be the standing one's mate, sitting on her nest. She would have moved by this time, either to come to the aid of the male or to join him in flight, if she were free to do so. The fact that she stayed put meant that she had eggs to protect and warm.

 

      The humans were intruders on a nesting site, troublemakers.

 

      But Veg had now seen this too. Embarrassed, he retreated. 'Sorry, pal,' he said. 'Didn't know it was your home. Thought you were just getting in the way. Sorry.'

 

      The bird watched him, standing unsteadily, neck crooked where it had been struck. The second bird watched also, from the nest.

 

      Veg, backing away, had forgotten where he was. He stepped off the narrow bank and toppled beautifully as his foot came down on water. The quarterstaff flew up as he, went over, flailing. There was a tremendous splash.

 

      Aquilon couldn't help laughing. The change from crisis to ignominy had been so sudden. Then, to cover up, she trotted to the bank to see what help she could offer.

 

      Circe stood a few yards away, watching but not participating. What had passed through the manta's mind as she watched this farce?

 

      The male bird peered at the scene but did not move either. As Veg staggered out, dripping, and Aquilon assisted him, it unkinked its neck and reached down to peck exploratively at the forgotten quarterstaff.

 

      The human contingent withdrew. The manta observer disappeared. The bird remained at the neck of the peninsula until contact was broken. Aquilon held back just long enough to sketch its proud portrait.

 

      They camped on the (calked) raft again, anchored south of the island. They consumed their respective suppers without conversation, and lay down together in the cabin when it became dark.

 

      'That bird is intelligent,' Cal said. 'I suspected as much from its foraging habits. Did you observe the way it reacted? None of the blind animal instincts. It was studying us as carefully as we were studying it.'

 

      'I wish you'd told me that was the bird we were looking for,' Veg complained. 'Here I was, trying to scare it away - I thought you wanted some giant!'

 

      Aquilon stifled her laugh. The unforeseen problems of communication! Veg must have imagined a bird proportioned on the scale of Brachiosaurus! The fabled roc...

 

      Then she thought of something else. 'How did you know how it foraged?' she demanded of Cal.

 

      'I followed its tracks, naturally.' She heard Veg stifling his own laugh, at her expense. She had overlooked the obvious, much as he had.    'I lost the trail in the marsh,' Cal continued, 'but I learned enough to convince me that the originator resembled class Aves about as man resembles class Mammalia. That was significant. So I asked the mantas to watch for it.'

 

      'Now he tells me,' Aquilon muttered chagrined. Of course a really intelligent bird would be a different matter. She, like Veg, had been thinking only in terms of size, and probably it hadn't occurred to Cal that either had misunderstood him. 'Now that I have seen it directly, I'm almost certain,' Cal said enthusiastically. 'No such creature walked our Earth in Mesozoic or even Cenozoic eras. This is Earth - but a parallel Earth, not our own. Very similar, but with certain definitive differences developing. And there is a displacement in time that this world runs about seventy million years behind our own, geologically. Perhaps there are an infinite number of alternates, each displaced by an instant of time instead of physical distance. Our connection happened to be to this particular alternate, Paleo - a purely random selection. We could as easily have landed, on a world removed by a single year, or by five billion years.'

 

      'Or one ahead of ours, instead of behind,' Aquilon murmured. Cal had not been joking about the implications being as severe as time travel. What Pandora's box was opening up for mankind with this discovery?

 

      'It may be possible to trace the entire history of our own Earth, simply by observing the progressive alternates, once the key to their controlled discovery is perfected. But in the interim we are free to manipulate this specific world to our advantage, knowing paradox is not involved.'

 

      There was something about that phrasing Aquilon didn't like.

 

      'I don't know what you mean, friend, but it doesn't sound good,' Veg said. What do you want to do with Paleo?'

 

      'Why, open it for human colonization, of course. It is ideal for Earth's population overflow. Same gravity, good climate, superior atmosphere, untapped natural resources, few enemies - apart from certain reptiles of this one enclave, and perhaps scattered others. This could be preserved as a zoo; it will be invaluable for research.'

 

      'Colonize?' Aquilon didn't like the sound of this any better than Veg did. 'This is an independent world. Who are we to take it over for our convenience?'

 

      'We are men, generically. We must consider the needs of men. To do otherwise would be unrealistic.'

 

      'Now let me get this straight,' Veg said in his play-dumb fashion. She could feel the tenseness of his body as he lay beside her. 'You say we should turn in a report saying that Paleo is A-O.K. for people to come in and settle, and make it just like Earth. And if a few birds or lizards get in the way it's their tough luck?'

 

      'Well, provision should be made for the fauna. I would not condone genocide, particularly in so fine a paleontological laboratory as this. But apart from that your summary is essentially correct. This is a wilderness area, and Earth needs it desperately; it would be a crime against our species to let it lie fallow.'

 

      'But the bird,' Aquilon protested, her heart beating too strongly. 'You said it's intelligent. That means Paleo is technically inhabited -'

 

      'Intelligent for Aves: birds. That can't approach human capability. But yes, it is most important that this - this Orni-sapiens be preserved and studied. It -'

 

      'Orn,' Veg said, simplifying again. 'In a zoo.'

 

      'No!' Aquilon cried. That isn't what I meant. That would kill it. We should be helping it, not -'

 

      'Or at least leaving it alone,' Veg said. 'It's a decent bird; it didn't jump me when it had the chance, and after I'd hit it with the staff, too. We don't need to lock it up or help it, just let it be. Let them all be. That's the way.'

 

      'We appear,' Cal remarked, 'to have a multiple difference of opinion. Veg feels that man can not sit in judgment over the species of Paleo, either to assist or to exterminate.'

 

      'That's what I feel,' Veg agreed.

 

      ' 'Quilon feels that the bird, Orn, deserves assistance, because of its apparently unique development as a creature distinct from Earthly genera. Obviously Orn is not common here, and may be in danger of extinction.'

 

      'Mmmm,' Aquilon agreed. Cal was that most dangerous of opponents: the one who took pains to comprehend the position of his adversary.

 

      'While I feel that the needs of our own species must take precedence. It is nature's decree that the fittest survive in competition, and if Man can control this world operating from a tiny beachhead in the Pacific, he deserves to and is required to. The fact that the animals here resemble those of our own past is irrelevant; our species must have room to expand.'

 

      'Lebensraum,' Aquilon whispered tersely.

 

      'Adolf Hitler's term,' Cal said, picking up the allusion Immediately, as she had known he would. 'But he used it as a poor pretext for conquest.'

 

      'Aren't we?'

 

      Cal shrugged in the dark.

 

      She felt herself getting flushed. 'Suppose some other species - maybe an advanced version of Orn - had felt that way about our own Earth?' she demanded. 'Suppose they had come when we were apelike primates, and used advanced technology to push us out?'

 

      'We'd have deserved it. We're still apelike primates.'

 

      'Maybe we should vote' Veg said.

 

      'No problem' Cal said. 'Are you ready, mantas?'

 

      From the roof came a tap - the contact of a manta's tail on the wood. Aquilon was startled, though she should not have been. They had probably come after dark and viewed the leaking sound waves, thus picking up the entire conversation. Cal had certainly been aware of the audience, and he seemed to have confidence in the outcome. Why?

 

      Veg was silent also, probably wrestling with similar concerns. How, she wondered hurriedly, would the manta mind view this crisis? They saw things in terms of their own Nacre framework, manta framework - carnivore, omnivore, and herbivore - with rights and wrongs being interpreted through this. Veg's vegetarianism had been the original key to contact with these creatures, since they had seen him as theoretically in need of protection from the omnivore of the party: her. It wasn't as simple as that, Cal had maintained; but as an analogy it would do. Of course she had shifted from omnivore type to herbivore type, while Cal had gone from carnivore to omnivore; apparently the mantas were now wise enough to the ways of man to accept these changes. All human beings were true omnivores, regardless of their diets of the moment; man's brutal nature denned him.

 

      'What do birds eat?' Veg inquired.

 

      It was a stupid question and no one replied. Veg knew what birds ate; he was a veteran birdwatcher. Funny, she realized now, that he had treated the Orn so brusquely. Perhaps he only identified with small birds, the seed-eating, fly-chasing kind. As a species, of course, birds were omnivorous.

 

      Omnivorous.

 

      The question had not been stupid at all. Suddenly she knew which way the manta vote would go. 'No' she said, trying to control the tremor in her breast. 'Don't vote.'

 

      'Why not?' Cal asked her. He knew his advantage, and was pressing it ruthlessly despite the mild words. In body he was small, in mind a giant - and that went for discipline as well as intelligence.

 

      'It's too important' she said, dissembling, knowing she could not prevail against him, and that Veg would be even less effective than she. Cal had the brain and the votes. 'Before, it was only where we wanted to go as a group, not a really critical decision. This time it's the fate of an entire world. Our world, or one very like it. This isn't the manta's business'.

 

      She saw the teeth of the trap and scrambled to avoid them. 'Colonization would destroy Paleo as it is, you know that. They'd decide the dinosaurs were a menace to tourists or navigation or something, and wipe them out. So we can't decide a question like this by ourselves.'

 

      'I was hardly suggesting that we should,' Cal replied calmly. 'We have merely to make an honest report to the authorities on Earth, and let them decide.'

 

      'But they're omnivores!' she cried, knowing this implied that she endorsed a dishonest report. Omnivore - she meant it as a description of character, not diet. The omnivores of the planet Nacre were utterly savage, with virtually no redeeming qualities, in her terms. This was in contrast with the innocuous herbivores and deadly but disciplined carnivores. The term 'omnivore' had come, for her, to represent all that was despicable in life. Man was an omnivore, and had already demonstrated his affinity to the Nacre breed. That ruthless action on Earth itself to eradicate potentially dangerous fungus spores -

 

      'So is Orn,' Cal said.

 

      'That isn't what I meant!' she exclaimed, defensively angry.

 

      'You're being emotional rather than rational.'

 

      'I'm a woman!'

 

      There was a freighted silence.

 

      Cal was right, but she knew he was wrong, ethically. Cal had decided against Paleo the moment he was assured that it was safe to do so. The mantas wouldn't care. The Earth authorities would be concerned only with exploitation of natural resources and the temporary relief of population pressure. They would much prefer to devastate another world, rather than to abate the mismanagement of the first. There was no one she could appeal to.

 

      'I can't participate in this,' she said at last. She got to hands and knees and crawled out of the cabin, leaving the men lying there separated by a woman-sized gap. She was dressed; the niceties of contemporary convention were ludicrous here.

 

      She stood aboard the raft in the gentle night wind, looking across the moonlit water toward the island. Large flying insects hovered about her head and tried to settle on her. She jerked her hood up and fastened the mesh over her face, batting it against the sides of her head to clear it of trapped arthropodic life. Then she drew on her gloves, so that no portion of her skin was exposed. The night was warm, and this confinement made her hot, but it was better than submitting to the appetites of the winged ones.

 

      It was stupid, it was cruel - but it would be worse to go along with this genocidal majority. She had witnessed the ways of man on Earth, and could not bear the thought of the rape of Paleo that was surely in the making. So - she had to go her own way, whatever that might mean.

 

      She looked over the black water. She would have to swim. At least that would cool her off! The chances were that no large marine predators were near. The reptiles didn't seem to be active at night, generally, and their size kept their numbers down. Still, she hesitated, sadly confused inside. She tried to tell herself it was because she knew Ichthyosaurus was a night hunter, because of those pumpkin-sized eyes ... but it was the separation from those she had thought lifetime friends that really dismayed her. How could she return, once she made this break?

 

      There was the scuffle of another person breaking through the cabin net, and Veg stood up beside her. 'Better your way than his,' he said.

 

      She experienced a choking surge of gratitude toward him. She had made her decision on her own, not presuming his. The ties between the two men were strong, however different their temperaments and physiques might be. She had not even thought what she might do, by herself, or how she would live. Now she was immensely relieved to know that she would not be alone.

 

      'We'll have to swim,' he said, echoing her own thought. 'You were headed for the birds, weren't you?'

 

      She hadn't planned that far ahead, but it seemed to fit. The schism had started with the birds, really.

 

      She touched his arm, not wanting to speak within the hearing of Cal, or even to gesture, knowing the mantas were watching. Cal was the weakest member of the group (physically!) and the raft required muscle to operate. Muscle the mantas could not supply. By leaving him, they were marooning him.

 

      'I'll check back in the morning,' Veg said. 'We'll work it out.' He dived into the water, making a phosphorescent splash.

 

      Relieved, she followed him.

 

      XIII

 

      ORN

 

      Well after dusk Orn lifted his head, disturbed. Beyond the normal noises of the night he perceived a differing manifestation, and in a moment placed it: the awkward progress of the monstrous mams.

 

      The confrontation of the day still distressed him. The really strange or inexplicable or completely unremembered bothered him because he did not know how to deal with it, and this recent encounter had been all of that. Mams themselves were familiar enough; they were everywhere, more plentiful by far than the reps even here in the heart of this enclave. Elsewhere on the continent they were larger and bolder and farther developed than were the primitive samples here. But nowhere did they approach the size of either Orn himself or any of the larger reps, except perhaps for their largest and stupidest herbivores. He had adapted to the changed situation in the world and learned to cope with the new creatures, before settling into this more familiar valley. But to be so abruptly confronted by bipedal mams larger than himself!

 

      That shock had very nearly cost him his life. He had stood bemused by the appalling gap in his memory, trying to fathom the life history of the species so that he might know how to deal with it. Size was only one feature of many; these mams were different. Their myriad peculiarities had rendered them nearly invisible to him at first. Only his prior practice in visualizing unfamiliar creatures in terms of familiar ones had enabled him to grasp their nature at all.

 

      Meanwhile, one of the creatures had approached and made contact. Orn, mindful of Ornette and their two precious eggs, had had to react to repel the intrusion.

 

      The mam had struck him with an inanimate object, another astonishment. Orn had never realized that such a thing was possible. Inanimate things could be used for roosting or nest-building, or even riding across rough water, but never for the work of claw or beak. Hitherto. What could it mean?

 

      And the final fluke: the mam, having by its alchemism rendered him vulnerable, had failed to kill him. The creature had instead plunged into the water and retreated, and the others with it. If they had come to fight and feed, this was nonsensical.

 

      He remembered the way he had spared the ptera, that first day of their nesting. It was possible to abstain from easy victory, in the absence of hunger. Yet that offered no comprehensible clue to the behavior of the big mams.

 

      Orn ruffled his wings restlessly. He was not equipped to think things out; his memory ordinarily made such effort unnecessary. But now that huge mam was coming again, in the night. Orn had to react, and to protect himself and their nest more effectively than he had before. No ancestor had faced this particular problem.

 

      At least this night attack was in character. The mams, like the aves, were able to move about as readily by night as by day, and a number preferred the cover of dark for their foraging. Indeed, many would not survive long in this homeland of the reps otherwise, for there were many empty bellies and sharp teeth on patrol by day, and mams were tasty morsels. Only by occupying regions too cold for the reps and by feeding at night had the mams prospered.

 

      But these were so clumsy! If the creatures - only two were coming this time - were hunting, they would never overtake their game so loudly. If they thought they were hiding, they were disastrously inept. Was it that they were so large for their type that they were stupid, like the brach swamp dweller whose plentiful young were such ready prey? But even the mam amblys were more careful of their own well-being than that!

 

      Yes, they were coming here. Orn raised himself from the nest and Ornette moved over to cover the eggs fully. One of them had to warm and guard the eggs at all times, and Ornette, gravid with the third, did not forage at all now. Three times they had made connection, and two of the eggs were incubating. The final one was due tonight, and a disturbance would be harmful. He had to guard the nest from every threat.

 

      He strode to the isthmus and waited for the two lumbering mams. Male and female, both grotesque in their inept giantism. What their mission was he could not know, for they lacked the furtive manner of egg stealers. But he would turn them back. There was a bruise under the feathers of his neck, from the previous encounter, and the muscles there were sore, but it had been an important lesson. He would not let such an object strike him again, not stand dazed. He would kill the first mam immediately and be ready for the second.

 

      They arrived. Orn waited, standing just behind the narrowest section of the isthmus so that they would have to approach singly. Perhaps they were egg stealers after all, depending on brute strength rather than stealth. He twitched the claws of one foot in the turf, ready to lift and slash ferociously. The eggs must not be imperiled!

 

      'He's there.' It was the male, making some kind of hissing growl that still did not quite resemble a challenge to battle.

 

      'Veg, he thinks you're after the eggs. Don't go near him.' That was the female, her growl more sustained and variegated. It was as though she were cautioning her mate about the coming encounter.

 

      The male halted in bright moonlight about four wing-spans from Orn. He held a length of tree in his paws - the same object that had surprised Orn before. It was in fact a substitute beak or claw, for the mam had no effective armament of its own. Orn visualized it as the latter, for it attached to the limbs. He would have to strike around it, diving for the open throat or gut.

 

      But the mam did not make an overture for combat. He stood for an interminable period, while the female stroked a twig against a flat object. Orn comprehended neither the action of the female nor the inaction of the male.

 

      'I've painted his portrait. We'd better leave him alone.' Noises from the female again, as she concealed her twig and tucked the flat thing under one forelimb.

 

      As though that senseless series of female squawks were a signal, the male dropped his length of barkless tree and took a step forward.

 

      'Veg!'

 

      There was no mistaking that cry of alarm. She understood, at least, that the male was on the verge of an encounter likely to end in disembowelment. Orn would not permit it near the nest.

 

      Still the creature approached, taking great slow steps, pausing between each. Now it had its fleshy forelimbs behind it, exposing his entire torso. It was only two wingspans distant, entirely unarmed and vulnerable; Orn could leap across that space and stab the large mam heart he sensed, then retreat to the superior position on the isthmus. But he held back, leery of attacking when he did not comprehend the meaning of the mam's actions and could not interpret them in terms of any similar creature. It could easily be a death trap for himself.

 

      Another step, and now he was aware of the tension in the mam. It was afraid yet determined, not in a kill fury. Did it want to die? Certainly it did not want to fight! It had made itself entirely vulnerable to Orn's beak or talon, while its mate whimpered behind.

 

      Then everything fell into place. These huge, awkward, bumbling things - they didn't know how to fight. They could strike out with pieces of tree, but were unable to follow up any advantage gained. Both would soon become prey to a predator rep unless they found sanctuary somewhere. So they had come to this isolated island, and, still afraid, had sought Orn's protection.

 

      He would ordinarily have killed it anyway, or at least wounded it sufficiently to drive it off, this alien male. He was not hungry for the meat. But the very nest that made him stand his ground against an unremembered antagonist also made him disinclined to kill unnecessarily. His being was suffused with the juices of cohabitation and protectiveness; he had his own mate to comfort and eggs to warm, and bloodshed made a poor nesting mood.

 

      The mam kept coming. Orn had either to kill him or let him pass, thereby extending his protection to the strange pair.

 

      He heard Ornette pant with the first laying pangs.

 

      Orn stood aside.

 

      The female crossed then, and the two mams joined appendages and skirted the opposite shore of the peninsula. Orn stepped backward toward the nest, anxious to be with Ornette in her time of pain, but compelled to watch the mams lest they make some hostile move. He was profoundly uncertain, more so than he had been when he spared the ptera, but at least he had avoided battle and killing.

 

      He came at last to the nest, and stood beside it for some time, listening to the mams while one wing touched Ornette's back. The creatures were behind the clustered pines, scraping the ground with their soft digits and uttering their ugly, drawn-out cries, but never coming toward him. They seemed to know that they lived on sufferance, and that the vicinity of the

nest was forbidden. He would have to kill them if they came near Ornette or the eggs, particularly tonight.

 

      Finally they settled down, and only their vocal noises persisted. That was their oddest trait: the perpetual and irrelevant sounds they made in their throats and mouths.

 

      'I wish there were some other solution.' The female making tones of disturbance. 'I hate to leave him alone like that.'

 

      'He's got a lot of know-how.' Now the male was replying with assurance. Their moods were not so different from those Orn shared with Ornette; only their vocalizing differed substantially. They employed drawn-out, modulated chains of sound in lieu of simple pitched honks. Apart from the clumsiness of the mode, it served. Everything about these ungainly mams was like that, however. Even their fur was matted and creased as though it had been baked in mud until it hung in chafing sheets. Nets of hair had fallen over their heads as well, obscuring their vision and smell perceptions and surely interfering with feeding.

 

      'He'll know better than to try to go anywhere.' The female was uttering modulations of self-reassurance now. 'The mantas will protect him.'

 

      'Yeah.'

 

      One thing about their continuing utterances: it enabled him to keep track of them without leaving the nest or straining his perceptions. He settled down beside Ornette, who was relaxing for the moment, and listened.

 

      'I wish we could get dry.' Female. 'I know it isn't really cold, but with this soaking and the sea breeze - I'm shivering.'

 

      'I brought a tarp in my pack.' Male. 'Make a passal blanket, if that helps. It's watertight.'

 

      'You're thoughtful, Veg. But the wet clothing is right to my skin, and the tarpaulin would prevent it from evaporating. I'll have to take my things off.'

 

      'I'll set up shop in the next gully.'

 

      'But you're cold too, Veg. You're just as wet as I am, and there's only one tarpaulin.'

 

      'I've roughed it before, 'Quilon. Don't worry about me.'

 

      They were doing something. Orn heard the rustle of something he could not identify. Not leaves, not bark, not tangled fur. Concerned, he stood up quietly and moved to where he could oversee the mam camp.

 

      The male was drawing flexible material from a rock-shaped object. It was as though a giant clamshell contained matted ferns. He spread it out, a single sheet, so that it settled over the female.

 

      It was all right. They were merely spreading bedding.

 

      'Veg-'

 

      ''s okay. The tarp's dry. I had it sealed in. Got a dry T-shirt for you, too. Wrap it tight to keep the bugs out though.'

 

      'Veg, you're not very bright sometimes.'

 

      'I know. I should've thought of dry clothing before diving in. In the morning I'll go back and pick up some. Now you fix yourself up, and I'll go down a ways and -'

 

      'Veg, if we sleep apart we'll both be cold.'

 

      'I know, but no sense getting everything wet again with my sopping rags. You're better off by yourself.'

 

      Orn realized that they were disagreeing with each other in some awkward mam way. The female wanted something but the male didn't understand.

 

      'Veg, remember when I spoke about making a choice?'

 

      'Yeah, 'Quilon. Back when we broke it up on Earth. I never forget things like that.'

 

      T made it.'

 

      The mams were silent for a moment, but Orn, watching and listening and sniffing, was aware of a continuing tension between them. Some kind of understanding was incipient. He flexed his claws, ready to move if the creatures attempted to make a night raid on the nest.

 

      'Yeah, I'm not very bright.' Male sound again: comprehension and triumph.

 

      Then the male put his soft mam digits to his own fur and ripped it apart. It fell from his body in wet lumps, leaving him plucked. The female stood up and did the same. Orn was amazed; he could never have moved his own feathers like that, or have endured the pain.

 

      The mams got down together and wrapped the big sheet around them, as though they were two hairless worms in a single cocoon.

 

      Orn listened for a while longer. Then he realized die significance of their actions. They were nesting! What had passed before was their odd man courtship, and now they were ready to copulate.

 

      Relieved, he returned to his own nest. At last he understood the complete motive of this pair of intruders. They had sought a safe place to reside during their mating and confinement, and so had chosen to make common cause with his own family.

 

      The big mams were not as stupid as he had supposed, merely strange.

 

      That night, while the mams embraced cumbersomely and made sounds reflecting labors of universal significance, and while the three ptera hung in cold silence from their branches, Ornette gave birth to the final egg.

 

      Peace and joy were upon the peninsula.

 

      The mams woke in the morning but remained in their bundle for a time, waiting for the sun to strike away the chill. As the ptera began to stir, the mams unwound, attended to their special toilettes, and climbed back into their ugly fur. They ate from a cake of scorched, impacted plant stuff and drank copious quantities of water from a strange container. Like all mams, they imbibed and ejected an appalling amount of liquid.

 

      'Look at the pteranodons!' The female was making her excited noises again. Orn, initially irritated by this constant and useless chatter, was becoming used to it. He accepted every creature for what it was, and it seemed the giant mams were noisemakers.

 

      Then a trach crossed the water from the mainland and sported about the peninsula, browsing for shore herbage. This rep fed mainly on pine needles and cones, grinding them up with its flat bill full of little teeth. Though it was large, standing four times Orn's height and possessing a flat, sleek muscular tail, it was harmless unless provoked. It needed its full height to reach the succulent (to it) needles growing from the lower branches of the tall trees. It was related to the para Orn had first seen dead beyond the mountain range, but lacked the elaborate bonework on the head. A para could thus outrun a trach, because it ran cooler; but the trach was of sturdier construction.

 

      Orn stood by the nest and let the rep gaze as it would, leaving its webbed prints in the muck. That was why the island location was so good: most large reps that were able to reach it and climb on land were those that ate neither flesh nor eggs, and so were reasonably safe. Like this good-natured trach.

 

      The mams also watched, but with greater caution. Their exclamations suggested that they were not accustomed to such proximity to the trach. Soon they relaxed, however, watching the rep's easy motions.

 

      'I better check on Cal.' And with that utterance the male was off, charging through the brush like a small tricer. The female remained to watch the trach play and feed.

 

      Ornette rose from the nest, and Orn covered the three living eggs while she exercised her legs and wings and cleaned herself off at the edge of the water. She had had a hard night, and was not entirely easy about the presence of the mams or the trach, but deferred to his judgment.

 

      Orn watched the female mam speculatively. Most mams did not lay eggs, of course; they gave live birth, like the ichthy rep of the sea. After the authority of the mating ritual of the night just passed, this process was surely commencing within this female. Would the two mams remain on the island for the denouement? Perhaps the mam litter would grow up with Orn's own in compatible proximity. This would be a curious phenomenon, but not objectionable, so long as there was no strife between them concerning tasty grubs and such. His ancestors had nested upon occasion in harmony beside troos and even ankys, though the parent reps never went near their eggs once they had been deposited. Rep nests were far more transient than those of aves, so it didn't matter. But his species had never shared territory with struths or tyranns or crocs of any age; indeed, Orn would smash and consume any eggs he found of these creatures. It depended on the type of rep.

 

      It depended on the type of mam, too. He would just have to be alert.

 

      It was during this contemplative interlude that the first tremor struck.

 

      XIV

 

      CAL

 

      It hurt Cal, this schism; he could not deny it. The group had come upon it almost incidentally, yet he had known it was brewing, and it had bothered him increasingly. They had been fortunate that it had not occurred on Nacre. Veg believed in life, however naively; Cal believed in death. Aquilon fell between, vacillating, but tended toward life. This was not so simple a concept as good and evil; both qualities were represented on either side of this issue. It was primarily a question of what was necessary.

 

      The four mantas understood that much, as they had demonstrated by their action at the orbiting station. Their view of man's endeavors was dispassionate, as was their view of the entire animal kingdom, since they were not of it. They remained with him because they knew that his approach to the problem of Paleo was realistic rather than emotional. Had it been otherwise -

 

      He sighed. Had it been otherwise, he would have relegated all Earth to limbo, for the mere love of Aquilon. He acted as he had to, but this did not alter his love for her. Nor did her figurative elopement with Veg affect this; he was aware that the simmering chemistry of heterosexual existence had to boil over at some point. They loved life, and this was the essence of life; the fact that Cal had increasing yearnings of his of that nature could not change his overall orientation. They were his friends, and he had more pressing responsibilities; he could not begrudge them their joy.

 

      Meanwhile, he had a job to do. Paleo was suitable for colonization by Earth, and no report he could make could conceal that. In fact, it was vital that he make the matter entirely clear, though this would sacrifice this beautiful world, for there were larger concerns. If the rape of Paleo diverted mankind long enough to allow information to circulate to those who could and would be stimulated to ensure proper protection for the other worlds of the alternate framework - the positive backlash - the end did in this case justify the means. Whatever Aquilon might think. This would necessarily entail the retirement of certain native fauna, and was certainly regrettable; but nature's way, properly guided, was best. No species could prevail by holding back. That was the way of self-extinction. The philosophy that saw virtue in the preservation of species and systems unfit to survive competitively - that philosophy was quaint but futile. Nature had no such sentiments.

 

      Cal studied the raft in the morning light. He would have to arrange to sail it back across the bay by himself, then make the trek overland to Camp Two for supplies. Then a longer

sea voyage back to their Paleocene camp, where the one remaining functional radio was located. After that it would be merely a matter of waiting. Earth would decide.

 

      It was not an easy journey he contemplated. Veg could have done it, but Cal was a far cry from that! Still, his philosophy accounted for this. He would make the attempt. If he failed, the report would not be made, and perhaps Veg and Aquilon would have their way. If he failed, he deserved to fail.

 

      His strength was not great, but it was more than it had been. He could rig the sail, tie it in place, and handle the rudder provided the winds were moderate and favorable. He would have to be alert for large reptiles and stormy weather, assuming that either could be avoided. How he would navigate the barrier reefs he did not know; possibly he could map a channel through them at low tide, then follow that course at high tide. He judged that the odds were against his completing the trip, but with proper application and caution he hoped to make a worthy run for it.

 

      'Ahoy!'

 

      It was Veg hailing him from the island. Cal waved.

 

      'How're you doing?' Veg called. Then, not waiting for an answer, the big man dived into the water and stroked for the raft.

 

      'I'm going back to the Paleocene camp,' Cal said as Veg clambered aboard. 'The radio is there, and I believe the winds are shifting enough to make it feasible.'

 

      'Feasible, hell. You can't make it by yourself. Why don't you talk to 'Quilon again? We shouldn't split like this.'

 

      Three, as the saying goes, is a crowd.'

 

      Veg covered up his embarrassment by going to the tied mound of supplies. Most of their equipment remained at Camp Two, but they had come prepared for several days. 'She needs some dry clothing, okay?'

 

      'She is welcome. Take some bread, too. She made it, after all. I'll be moving the Nacre out soon.' There had not been any official division of spoils, but it was tacit: Veg had the woman, Cal the raft. And the mantas.

 

      'You'll kill yourself.'

 

      Cal shrugged. 'Death is no specter to me.'

 

      'Here.' Veg busied himself with the sail, hauling it into position and tying it securely. 'If you get in trouble, send a manta.'

 

      They shook hands awkwardly and parted. Already the Nacre was tugging at the anchor.

 

      The wind was fair and gentle, the sky overcast, and progress was satisfactory. The mantas sailed out over the water, stunning fish with their tails. Cal scooped them in with the net and piled them aboard the raft so that the mantas could feed at leisure.

 

      It was interesting that the sea here was completely Paleocene. No ammonites, no rudists. Would Aquilon have dreamed about the rudist bivalve if he had described it to her as another typically Cretaceous sea creature? Only the reptiles had retained their hold on the sea, as part of the enclave. What did this signify about the relation of land and sea forms? There had to be some continuing link between the reptiles of land and air, so that they became extinct almost together...

 

      The island was a mile astern when the tremor came. The water danced as though rain were hitting the surface, but there was no rain. The mantas, disgruntled, closed hastily on the raft and boarded. Debris sifted down from the trees visible along the shore, and dust came up in peripheral sections of the valley.

 

      A tremor - no more than fifteen seconds in duration, not really severe. Cal did not react with unreasoning dread. Perhaps this little shake signified nothing - but it could be the prelude to a far more violent siege.

 

      Veg and Aquilon were on the island, stranded there until they could construct a second raft. Certainly they would not attempt to swim to the mainland during the heat of the day; the carnivores of water and shore forbade it. But of course there was no security from an earthquake. They were as safe on the island as anywhere. Perhaps safer, when the great land predators, surely roused into anger by the shake, were taken into account.

 

      He could return, but it would not resolve their interpersonal dilemma. The arguments had been made, the positions clarified. Best to continue as he had planned.

 

      In the distance, in the strait between the islands Aquilon had dubbed Scylla and Charybdis, he made out animate activity. The water dwellers had indeed been shaken up by the tremor, and were casting about, trying to flee or attack but finding no way to isolate the cause. Cal decided to steer well clear of them. Most were far smaller than Brachiosaunis, but many were more predacious, and even a herbivorous dinosaur was dangerous when alarmed, as the battered craft testified.

 

      Tremendous pteranodons sailed in the sky, the only creatures unaffected. No - as he watched, the winged reptiles changed course en masse. The wind had shifted, as though blunted by the tremor.

 

      That meant trouble for him too. He had traveled under fair auspices so far, but any change in the wind would be the worse for him.

 

      He untied the sail and began to haul it down. Now his lack of strength was critical, for what Veg made seem easy was a tremendous strain on his own resources. The sail, under tension, resisted his efforts.

 

      Then the wind shift caught up. The sail fluttered violently as it was struck almost at right angles, and the raft began turning. Cal knew how to adjust the sail and use the rudder so as to tack into the wind, but he also knew that he had neither the agility nor the strength to perform the coordinated tasks required. Sailing a clumsy raft was at best a two-man job, and tacking took muscle.

 

      He did the next best thing. He steered the Nacre around forty-five degrees, heading northwest instead of west. This would bring him to land too soon, but seemed to be his safest course.

 

      The mantas perched on the cabin roof, unable either to assist or to offer advice.

 

      All too rapidly the Nacre came at the shore. This was the swampy region where certain tribes of duckbills foraged, but none were in evidence at the moment. Just as well. They were not inimical to man, but would have reacted unpredictably to a charging raft.

 

      Now was the time to drop the sail, but the line was still jammed. The Nacre was diving relentlessly for the bank of land, carving a ragged course through the water plants.

 

      The mantas dived for the sides. So did Cal.

 

      He hit a cushion of soft plants and took in a mouthful of warm, slimy, but not salty, water before finding the mucky bottom with feet and hands. The depth here was about a yard.

 

      The Nacre ploughed on, slowed by the thickening growths. Then the keel scraped into something more solid than the bottom mud, and the whole thing crunched to a halt, upright and listing only momentarily. The jammed rope let go, and the sail dropped resoundingly to the deck, releasing the raft from the urging of the wind.

 

      Cal had taken his plunge for nothing.

 

      He waded up and sought the crude anchor. This might not hold against a determined offshore wind, but again there was nothing better he could do. He would have to leave the Nacre and hope it remained secure for a day or two, until he could return. He was, at least, on the right side of the river.

 

      He donned a small pack, taking only enough baked fish to last him a day, since he hoped to pick up supplies at Camp Two. He would be foolish to wear himself out prematurely, on this easiest leg of his journey.

 

      As an afterthought, he took his quarterstaff too.

 

      It was now early afternoon, and he knew he could not make the twenty miles the compass indicated before dark. He would have to husband his strength and do the job in stages. Time was as critical as survival.

 

      He trekked through the slough all afternoon, resting more frequently than he needed to. His strength was for the moment his most precious commodity, and he guarded it jealously. The mantas stayed with him though they would have been happier on their own; they were evidently concerned for his safety. By dusk he had achieved higher ground. He threw himself down, eyes closed, not bothering at first with any formal bedding.

 

      Veg could have made this distance in an hour, he knew. But to Cal it was a victory, for a year ago he could not have made a tenth of it. He was tougher than he had been in a decade, and he took an unobjective pride in it.

 

      But he still assessed his chances of success at less than even.

 

      He ate a salted fish for breakfast and moved out. His legs were stiff, but he felt stronger than ever. This was the first time in many years he had traveled by himself, and he was pleased to discover how well it was going. He was making much better time on this firm terrain.

 

      There were more deciduous, broad-leafed trees than he had supposed at first. Counting them idly, he found that fully a third of the substantial growth were familiar hardwoods - beech, birch, maple, ash, elm, and so on. Though the typically Cretaceous flora predominated, the balance was even now shifting to these newer types. The land like the ocean, was advancing relentlessly into the Cenozoic Era. Only the reptiles lingered.

 

      By noon he was within five miles of the camp. The intricate distance-gauging compass assured him of that, since it had been keyed to Camp Two. He stopped to eat the last fish and sup water up from a small rain-formed pond, and the mantas ranged out to bring down their meals too. He was not worried about nourishment; the mantas would gladly kill for him if that became necessary, and show him the way to fresh water. He would spend the night in the lean-to, then attempt to make the return trip in one more day. There would have to be many such journeys, of course, for he could not carry much at a time - but the exercise over a familiar trail should toughen him up for the major journey ahead. Perhaps he could fashion a harness-drag, and transport a greater weight at one time. He felt better able to cope than ever before.

 

      Hex came in, tail snapping. Trouble!

 

      A predator dinosaur had come across his trail and was pursuing him. The mantas had tried to distract it harmlessly, but it was intent on one scent. This was what they had been alert against. A big one. Hex clarified: Tyrannosaurus Rex, king of the camosaurs.

 

      The creature could be stopped, of course. The mantas could harass it and probably blind it. Tyrannosaurus was far larger than the omnivore of Nacre, but no more dangerous to the swift manta. Four against one -

 

      'Do not attack it,' Cal said.

 

      Hex didn't understand.

 

      'This creature's world is on trial. If I get to the radio and send my report, my people will come and exterminate the biological system that now obtains. Not all at once, but over the years, the centuries, until the only dinosaurs remaining are caged in zoos, and the same for most of the primitive Paleocene fauna. Modern mammals will be introduced that will compete aggressively with the less sophisticated natives, and the trees will be cut for timber and pulp and the rocks mined for precious minerals. So Tyrannosaurus is fighting for his world, though he doesn't see it that way. If the reptile brings me down, the report will not be made, and man will not come here - at least, not quite so soon. If I escape the reptile, I will have vindicated my right according to the implacable laws of nature, to supersede it on Paleo. It is a contest between us, and the prize is this world.'

 

      He had issued a statement whose entirety they could hardly be expected to grasp, but it seemed better not to confuse things by attempting to simplify a difficult concept. The mantas should understand that he did not want them to intercede on his behalf, and that he had reasons that were sufficient for his own mind. That should be enough.

 

      The other mantas came up, and an eye-to-eye dialogue followed. Would they acquiesce?

 

      'Let me meet Tyrann alone,' he repeated. 'You watch, but do not interfere. Mammal against reptile, the chosen champions, one to one,'

 

      Hex snapped once. Yes, they accepted it. The mantas understood the rite of personal combat.

 

      The four spread out to the sides and disappeared amid the cycads. Cal was on his own.

 

      But not for long. A mile back, the giant was coming, crashing through the brush horrendously.

 

      It had been easy to commit himself, for that was necessary by his definitions. It would not be as easy to survive the consequence of that decision. He was hardly the best representative of his species or class for such an encounter. But that was the way circumstance had offered, and he was ready to abide by nature's verdict. He had never been one to avoid confrontation with death.

 

      Cal waited where he was. He wanted to face his opponent. It would be no good for him to sneak away, even if that should fool the reptile. He had to stand up to Tyrann, let the thing know he was challenging it. Then he could make his escape, if it was in him to accomplish it.

 

      The ground shuddered, and not from any geologic tremor. Tyrannosaurus was closing in, unsubtly. Every step rocked the land, and the crashing of saplings became loud. This was the pinnacle of reptilian predatory development; no more massive carnivore had ever walked the earth.

 

      The slender fern trees swayed aside, as though reaching to the ginkgo for comfort. A terrified bird flew up. Through the palm fronds poked a gaping set of jaws - fifteen feet above the ground. Then the whole of it came into view: seemingly all teeth and legs, so tall that a man could pass upright under its thighs and tail without stooping. A roar like none ever to emanate from a mammalian throat shook the air, and the tiny cruel eyes peered down. Tyrann had arrived.

 

      XV

 

      AQUILON

 

      'He's sailing the Nacre' Veg said as he reappeared. 'Going back to the radio and sending the message.' He threw down the pack of supplies he had brought from the raft.

 

      Aquilon was appalled. 'He can't possibly do it by himself!'

 

      He shrugged. 'Can't stop him from trying.' But his jaw was tight.

 

      He knew the mantas represented a formidable bodyguard, but there were things they could not protect Cal from. Drowning, physical injury, heatstroke -

 

      Still, Veg was right. If Cal insisted on attempting a suicidal journey, that was his concern. At least, so long as the break between them continued.

 

      If only it were something other than the future of a world at stake! She would gladly have gone along with Cal for the sake of unity on any lesser matter. But his report to Earth would damn Paleo by its praise, and she could not go along with that. It would violate all her most cherished, if uncertain, principles. The wolf should not be loosed at the lamb, not this way.

 

      She felt guilt for either outcome: Cal's success or his failure. She knew he would not change his mind. If he lived, Paleo would die.

 

      Now, too, she felt uneasy about her night of love with Veg. She had made her choice - but she had done it because of the convenience of the moment, and that was not far clear of prostitution, in retrospect. And she suspected from Veg's silence on that score that he felt the same. They had wronged Cal, whatever the merit of their respective positions. The Orn birds went about their business first one sitting on the nest, then the other, but usually the female. There were eggs, naturally; she had not glimpsed them, for the birds were sensitive about any human approach to the nest. But nothing else would account for such care.

 

      The first day passed in beauty. She watched the Trachydon, the large duckbilled dinosaur, feeding among the pine trees. It was sleek in the water, with webbed feet and a tail flattened like that of a crocodile. When it stood on land it was fifteen feet tall, resembling an outsize kangaroo, and the hind feet were revealed as possessing tripartite hoofs. Duckbilled - but not ducklike.

 

      Trachydon spent most of its time chewing, as though its digestion not only began in the mouth but ended there. Its hide was pebbled, without scales or other armor, and the play of the creature's musculature was quite clear underneath the skin. Its underside was whitish, reminding her of a snake. Its sheer size fazed her at first, but Trach was really quite likeable when familiar. It also seemed to pose for her, remaining impossibly still except for its jaws, and she painted many portraits. She was sorry to see Trach go, once its belly was full of pine.

 

      At night the pteranodons returned to their bough to sleep, and that was another impressive spectacle. She had somehow imagined all dinosaurs to be ravening monsters or dim-witted behemoths, before coming to Paleo; this day on the island, watching Trachydon and pteranodon in life, banished that prejudice forever. These reptiles had individual personalities and problems, and were bright enough about the latter.

 

      She also saw, that first day, the raft sailing before the wind, angling in toward the mainland, and finally anchoring there. She knew why: the wind had shifted after the tremor, and Cal had been unable to sail directly back to Camp One. At least he had made it safely to shore.

 

      The second night she and Veg slept under the tarpaulin but did not make love.

 

      Two nights and a day on an isle very like paradise - but the tension was cruel. What was Cal doing? He was so small, so weak; he could be lying exhausted in the swamp...

 

      No. The mantas would come back and report. He must be all right.

 

      Still-

 

      'One's coming!' Veg called, looking up from the new raft he was building.

 

      She ran to his side to see. A lone manta was speeding across the water toward the island. Circe!

 

      The story did not take long: a tyrannosaur was after Cal. He had forbidden the mantas to help. Circe departed.

 

      'The crazy fool!' Veg cried. 'He's suiciding again!'

 

      But it was not that simple. Cal wanted to fight the dinosaur, according to Circe. Ritual combat.

 

      'I know how he thinks!' Veg said. 'He wants to prove he can do it by himself. And he can't.'

 

      'You mean, prove he's better physically than a dinosaur? That doesn't sound like the kind of thing -'

 

      'That he can get through and send his message, no matter what. Our leaving him didn't stop him, Tyrann won't stop him. That makes it right, he figures.'

 

      Suddenly she saw it. The mammals against the reptiles, each represented by its most advanced stage, one individual meeting the other on the field of honor. The decisive combat. The carnosaur had size and power; the man had brain. It was a fair compromise, a way to settle an otherwise insoluble dilemma. If Cal won, he would send his message and be justified in the spoils; if he lost - well, it was an answer, and he had chosen the way to come by it.

 

      'I'm going over there,' Veg said.

 

      'Veg-'

 

      'I'll have to swim to the mainland and run along the shore. Cross the river up where it's narrower, nearer Camp Two. Hope I can pick up his trail, or maybe a manta'll show me. Fastest way. Might make it in time to haul him out of there alive.' He was fastening his clothing for swimming as he spoke.

 

      'Veg, I think we should let him do it his way. On his own. That's the way he wants it.'

 

      'He'll get killed!'

 

      She hesitated. 'Maybe - that's best.'

 

      Veg stiffened. Then, so suddenly that she did not realize what had happened at first, he hit her. His arm came back in a hard swing that caught her across the side of the head and sent her reeling to the ground.

 

      By the time she righted herself, he was in the water, well on his way. She must have blacked out momentarily, for she had not seen him go.

 

      Her hand lifted to touch the stinging, swelling side of her face gingerly. His wrist had struck against her cheekbone; there was no blood. Veg had not even paused to see whether she was hurt. Thus eloquently had she been advised of his first loyalty.

 

      Had she worried about coming between these men? She should have known there was no danger of that!

 

      Yet it still seemed to her that Cal was not only courageous, but right. She could abide by the decision, made that way. Veg, long us he had known Cal, loyal as he was, did not understand. Nothing would be settled if he got there 'in time'.

 

      She turned to find Orn - yes, that was the name that fit - standing behind her. He was close and quite formidable, suddenly, with myriad tiny scars showing on his legs and beak, and some feathers not completely grown out to replace lost ones. He could have struck her down easily while she stood bemused, but she sensed no hostility in him.

 

      Hesitantly she reached toward him, experiencing an overwhelming need for companionship of any type. She was alone now, on a strange world, without any genuine hope of seeing either man again. Cal's mission was suicidal - but so was Veg's. It might be that the only company she would know henceforth would be that of the big birds.

 

      Orn opened his mighty beak and caught her hand within it - and did not bite. She felt the knife edges of his jaw and knew that her fingers could be severed cleanly by its vicelike compression. But the touch was token.

 

      Then Orn dropped her hand and returned to his nest. It was as though he had touched her in comfort, but not remained to make an issue of it. She was deeply grateful for the gesture.

 

      She roused herself after a time and foraged for edible roots on the main body of the island, since her supplies would not last indefinitely. Her heart was not in it, but she did have to eat. She found a lone banana plant, but the fruit was not ripe. It was afternoon, and she knew nothing of the progress of the two men. She might have expected Circe to stay with her, but the manta was away on some other business. The rapport she had thought she had with the creature of Nacre was fading.

 

      A second tremor came - a stronger one. The ground did not shudder, it rocked. It was as though the soil had turned liquid, and she was riding the waves. She kept her feet with difficulty.

 

      She had a sudden and ugly premonition of what such a quake would do to a nest built on a rock, and to the fragile eggs within that nest. She ran swiftly back to the peninsula as the motion of the ground subsided.

 

      The site of the nest was chaotic. Both birds were standing beside the rock, fluttering their vestigial wings. The worst had happened.

 

      They did not challenge her as she approached, too upset, she realized, to maintain their guard. The nest was damaged but largely intact. The eggs -

 

      Fragments of thick shell projected up, and white and yellow jelly filled the base of the main cavity. The eggs had been shattered by the quake. The birds seemed stunned by the calamity. She visualized the mutilated corpses of human babies in place of the smashed eggs, and thought she understood how the Orns felt.

 

      But one shell appeared to be intact. Aquilon touched it hesitantly with a finger and found it warm and firm. It was eight or nine inches long and slender in proportion, the surface rough. She reached both hands around it and lifted the object out, careful not to let it slip in the slick fluid around it.

 

      Both birds were still, watching her helplessly. 'This one's all right,' she said.

 

      From somewhere in their throats came an incredulous, hope-dawning cooing.

 

      She carried the egg to a dry hollow and set it down. 'Keep it warm,' she said. 'You can make another nest.' She backed away.

 

      After a moment the female - Aquilon thought of her as Ornette - came over and studied it. Then, in a kind of nervous collapse, she sat on it.

 

      But one crisis had passed only to lead to another. The odor of the broken eggs had attracted a predator. Sleek and very long in the water it came - a giant crocodilian reptile, not closely related to the modern crocodiles of Earth but similar externally and every bit as dangerous. Twenty feet from snout to tail, it hauled itself out of the water at the rocky mouth of the inlet and scrambled overland toward the nest.

 

      Orn charged it, squawking loudly and beating the air with his wings, but the armored reptile only snapped sidelong at him and continued without pause. Nothing Orn's size could hurt it seriously; that was obvious.

 

      Would it stop with the nest? Aquilon knew it would not. It must have swum over from the main swamp, for she had seen nothing like this near the island before. The duckbill would hardly have been so casual, either, had it sniffed this predator. Perhaps the quake had jolted it from its accustomed beat. It was hardly in a mood to be reasonable by any mammalian or avian definition. Now that it was here, it would pursue all food available - and that meant the third egg, and the bird protecting it, and probably the stranded bipedal mammal, herself, as well.

 

      Aquilon fetched her quarterstaff. She held it by one end and ran at the crocodilian as though she carried a lance. The forward end struck the creature's leather-tough neck and bounced off, denting it only slightly but delivering a severe hit to her.

 

      The long head swung about, jaws gaping. Aquilon braced herself and swung the pole like a club, striking that snout resoundingly. Unhurt but annoyed, the reptile charged her, its horrendous teeth leading.

 

      Fighting instinctively, she drove the quarterstaff lengthwise into its mouth. To her horror, the entire pole disappeared that orifice, and the snapping jaws barely missed her hand. She scrambled back.

 

      But it was enough. The crocodilian coughed and shook head, pained by the object in its throat. Unable for the moment either to swallow it or spit it out, the monster abruptly plunged into the water. It swam to the rocky inlet mouth, jammed itself between the stones so violently that it left scrapings of flesh and departed. As it passed from view, she heard its teeth clashing together as it sought vainly to bite down on obstruction anchored neatly between the dental rows.

 

      Aquilon sat down hard, discovering herself panting desperately. She had expended more energy than she realized during the excitement, and was nearly exhausted. But she had won: Her omnivore heritage had come to her rescue and she has driven off the predator.

 

      At the cost of the only weapon she had. Well, she could make another.

 

      Was this the type of creature she was striving to protect from Earth's ravages? A twenty-foot, merciless egg-eating carnivore?

 

      With this in the water, and others like it - had Veg even made it to the shore?

 

      Dusk was coming - where had the day vanished! - and with it the pteranodons. Aquilon got up, still too tense to eat, and began to walk to the tarpaulin on the other side of the peninsula.

 

      Orn blocked her way. She stared at him blankly, then tried to step around. He blocked her again, herding her back by spreading his wings. They were larger than she had thought; their total span, tip to tip, was about five feet. Far too small to enable him ever to fly, but handsome in their own right. The under surfaces seemed almost to glow. Some of the feathers had been freshly broken off, courtesy of the crocodilian. But Orn's manner was not threatening.

 

      She turned and walked toward the makeshift nest, now buttressed by bits of moss Ornette had found within reach. Orn followed. She got to her hands and knees beside Ornette, then curled up and lay beside the huge bird. Orn settled down at her exposed side, spreading one wing to partially cover her body. It was like a thick, warm blanket - and yes, it made her feel immeasurably safer.

 

      No - this was what she was fighting to save! This unique, intelligent family, related to her only in spirit.

 

      Comfortable and secure between the two great warm bodies, slept.

 

      XVI

 

      CAL

 

      It was mind against matter. The mind of man against the itter of reptile. One would prove itself superior in this test, and to that one would go this world. That was the way it had to be. Except for one small factor -

 

      Tyrannosamus rex - the tyrant lizard king - charged down on him, banishing that speculation. Yet in this moment of confrontation he had an aberrant vision of Aquilon, so lovely she blinded even his mind's eye. She would have understood this, had she known of it, and perhaps she also would have approved. Had he known this opportunity would arise, he could have arranged to avoid the schism in the human party. But Veg would not have gone along. The big man tended to overlook the nuances of interspecies morality, and so relied on conformance to a simplistic code. Thou Shalt Not Kill - except when threatened. And who could say what constituted a legitimate threat? The corollary was taken as Thou Shalt Not Eat the Flesh of Any Member of the Animal Kingdom - forgetting that man was a natural predator, owing much of his progress to his diet. So how could such a code solve or even ameliorate the myriad problems of the species? No matter; conform.

 

      All this, in fragments, while Tyrann crashed toward him, head swaying from side to side for balance, eyes fixed on target. The reptile was now within a hundred feet: twice its own body length, five times its height. It was moving forward in a roughly straight line at some twenty miles per hour, ten tons of malevolence. Perhaps it was disappointed in the size of its quarry, hardly worth the effort - but this did not slow it.

 

      No, Veg would not have understood. So it had to be this way: a battle without witnesses, except for the alien mantas. If he lost, his friends would assume he had been suicidally foolish. If he won, lucky. But he knew, and that was what counted.

 

      Time to stop reminiscing and start competing.

 

      Cal waited until Tyrann was within a single body length, calculating the time factor. Fifty feet at twenty miles an hour would be about a second and a half until contact - too brief for fine adjustments on its part. The maneuverative advantage did not lie with size. At that critical point - fifty feet - Cal dodged to the side.

 

      His velocity from a standing start was slower than that continuing motion of the dinosaur, but he had a smaller distance to go. He covered only fifteen feet before the six-inch teeth clashed where he had been, and another ten by the time the tremendous thigh and foot rocked the ground behind him; But the margin had been sufficient.

 

      Tyrann, discommoded by the miss, drove his nose into the dirt and came to a roaring halt. He lifted his mottled head, dewlap stretching, small eyes peering balefully about while leaves and twigs tumbled wetly from his jaws. It took him a moment to realize what had happened, but not a long moment. He was a predator, and few of that ilk were stupid or slow when hungry. He had been fooled once by a seemingly petrified morsel, but now he knew it for one of the quick-

footed mammals, and he would not underestimate its agility again.

 

      Cal, meanwhile, had made it to the nearest large palm tree, holding his quarterstaff aloft. He had won the first pass by utilizing his advantage of mobility. His shorter neural chains permitted faster responses; the distance from his brain to his feet was a fraction of the corresponding connection in the dinosaur. But the overall advantage remained with Tyrann, who could outrun him on the straightaway and catch him when the dodging slowed.

 

      Of course even that was not clear-cut. Tyrann had a great deal more mass to sling about, and a sprint would wear him out rapidly and overheat his tissues. Cal could probably outrun in the long run, if he survived the short run.

 

      The reptile sniffed the air and oriented on Cal's tree. There, too, was a weapon: the predator's well-developed nose. There was room in that huge head for capacious nasal chambers, and though the gleaming teeth were superficially impressive, they were dependent on the functioning of that nose. The eyes and ears were less important, since Tyrann was not a sneaker. He required one sure way to locate his prey, and the nose was it.

 

      Fortunately for Cal, the sense of smell was ineffective as a guide to the whereabouts of a fast-maneuvering creature. Cal could not hope to hide long or steal away any great distance, but right now he could force the carnosaur to use his less effective senses. That was the function of his brain: to divert the contest to his opponent's weaknesses, his own strengths, and thus prevail.

 

      Maybe.

 

      Tyrann charged the tree. It seemed ludicrous to imagine weakness in connection with twenty thousand pounds of predator, or of strength in his own hundred pounds. But - that was the thesis he intended to prove.

 

      Tyrann knew about trees. He did not bite the palm or crash to it. His forelimbs, smaller than his own great toes, were less; they were hardly more than toothpicks projecting from neck. Literally: Tyrann cleaned his teeth with those vestigial, two-clawed arms, though even that made him contort is neck to make the connection. So it seemed that he could not get at Cal, so long as the man kept the broad trunk between them.

 

      Not at all. The dinosaur turned and swept his massive tail against the trunk. The tree vibrated; loose fronds dropped, forcing Cal to cower. A spearlike dry seedpod plunged into the ground next to his head: the thing was a yard long and well pointed. He jumped away from the tree, realizing how hazardous its cover was - but stopped, realizing that that was what Tyrann intended.

 

      The tail itself whipped around, a scarred column of flesh, and caught him smartly on the hip as he was trying to get back to the palm. Its force had been broken by the trunk, and its vertebrae did not permit much flexibility, but the residual nudge was enough to send him lurching away from his cover again. His quarterstaff was jolted wide, and he had no chance to recover it. Now he lacked even token armament.

 

      And of course Tyrann was ready. He pounced.

 

      Cal ducked under the dinosaur, avoiding the gaping jaws again by the surprise of his motion. Tyrann had anticipated his flight away from him, and had compensated accordingly. Cal  bounced off the hanging skin of the reptile's neck, scraping his arm against the horny creases, and jumped for the tree again, panting.

 

      He was thankful he hadn't tried to escape by climbing the palm. He would have been an easy target for that tail. Tyrann could not use it to reach or clutch or coil, but that brute banging against the base of the tree would have shaken almost anything loose.

 

      Tyrann swung around again, watching Cal with one eye. The tail lifted, swung.

 

      Cal didn't wait for it this time. He sprinted away from the trunk, eyes open. As the tail struck and whipped over, he threw himself down flat and let the tip pass over him. Immediately he was up again and running for the next tree, legs and lungs straining.

 

      Tyrann let forth a bellow that sounded like gravel being dumped on a metal roof. He followed. Cal didn't stop at the tree; he passed it and angled for a small forest of firs he saw a few hundred feet ahead. His breath rasped in his throat, saliva streamed back across his cheek, and a pain in his side blossomed into a square foot of agony, but he could not stop.

 

      The dinosaur was impeded by the trees, since he had to circle them with wider clearance, but still was making better speed. His two feet came down like pile drivers, shaking the earth with an oddly measured beat

 

      Cal's heart was pumping harshly, and now his entire chest aflame. He saw that he could not make it to the pines, the spruce. Tyrann should be getting winded himself by this time - but it seemed that the dinosaur's strides were so long that this pace represented walking, not running, and so was not tiring. Cal dived behind a leaning oak and propped himself against it, too fatigued to do more than watch Tyrann.

 

      But here he had a fortunate break. The small-brained reptile had forgotten his quarry's predilection for changing direction, and charged on by the tree. Then, realizing the error, Tyrann cast about, but could not immediately recover contact. The smell of the mammal was stronger behind than ahead, and that did not make immediate sense to the reptile.

 

      Cal slid around the tree, aware that the accidental respite thad probably saved his life. But he knew very well that the war was not over; this was only an intermission, and a momentary one.

 

      Tyrann got his bearings and approached the tree. This time he waited to see which way Cal would bolt, not aware that the man had scant energy left to move at all. Yes, the dinosaur learned by experience - but not quickly enough, in this case. He lunged ahead when caution was best, and practiced caution when the direct approach would nab the prize. But that was his handicap: he was bright enough for a reptile, but hardly in the intellectual league with a man.

 

      The truth was that Tyrami would be better off giving up on Cal and looking for some careless upland-dwelling baby Brachiosaurus; those young did not reside in the water until their developing mass required it, and by then their numbers had been thinned to the verge of extinction. The adult female Brachs made annual pilgrimages upland to lay their eggs, and they too would be easy harvest for Tyrann. But this dinosaur had determination; he had settled on Cal as prey for the day, and would not give up. Cal respected that; this was a worthy opponent, over whom a victory would be meaningful.

 

      By the time Tyrann decided that the prey was not going to move, Cal had recovered the better part of his wind, and the pain in his bowels had abated. Oddly, he felt stronger than ever, as though tempered, as though his exertions had been pouring energy into him rather than drawing it out. This was possible: his weakness had been a symptom of an Earth-nurtured psychological syndrome, rather than anything initially physical. At Nacre he had tasted his first hint of freedom from it, aboard that sparsely populated world and with staunch companions. On Paleo he had his second experience - and though there were elements of disharmony, the overall effect was beneficial. And by this very chase he was resolving the last of that internal conflict. The long agony of indecision was over; he would prove himself - and his species, and his genus, family, order, and class - or die. He did not need to cripple himself any longer.

 

      So now, perhaps, the bodily resources that had been so long suppressed were reappearing, and he was ready for the dinosaur. It was a good feeling.

 

      Tyrann lunged at the tree, but this time did not swing about to threaten with his tail. He put his head beyond the slanted, trunk and stopped.

 

      Cal scooted a quarter of the way around, but halted when he saw that his opponent was there too. One giant leg came down beside the tree, while the nightmarish head descended from the opposite side. Tyrann could close the circle, when he happened across the right technique!

 

      But with difficulty. This was an unusual maneuver, and the dinosaur's reflexes were geared more for crashing through than for curling around. The closure occurred slowly, and the tail could not make it at all. The highly flexible neck was the principal instrument, coming to meet the tremendous thigh - Cal between.

 

      Saliva dripped from the grinning mouth, spilling over the double-edged teeth. The stench of reptile was oppressive. Cal peered into the near eye, just a yard away and huge from this vantage. The lower jaw widened just-below it, making anchorage for bulging facial muscles. The skin was rough, covered irregularly with tubercles, puckered in the region of the ear hole, and hung below the chin in a kind of extended wattle: the dewlap. Oh for the lost quarterstaff now! He could have; used it to poke out that eye!

 

      He glanced down, seeking some weapon, but there was only loam and acorns. A handful of coarse gravel hurled into that eye might start the job; but acorns?

 

      Slowly the jaws parted, the lipless skin peeling back from every dagger-jagged tooth, and sliding across the muscle-filled fenestrae, the windows in the skull. The alien reptilian breath blasted out, hot, not cold. It was a misnomer to describe reptiles as cold-blooded; their body temperatures were variable, determined by external conditions and exertion. In this warm valley, the reptile ran about as hot as the mammal and functioned about as well.

 

      The stunted forelimbs turned out to be as large as Cal's own arms, their claws long and sharp. Useful for holding the slowly dying meat firmly against the mouth, certainly: much as a busy executive might hold the telephone receiver against his ear by hunching his shoulder, aided by a little harness. Hardly essential, but useful upon occasion.

 

      One tooth was broken, leaving a gap, and the gum there was black. Tyrann's temper could hardly have been improved by that recent accident! But already the replacement tooth was pushing up.

 

      This was a strange situation: he was about to be bitten in half, in slow motion! If he ran for it, Tyrann would catch him; he could see the tension on the ponderous leg muscles, ready for that forward thrust around the tree. But if he remained -

 

      Closer. Tyrann's nostril, inconspicuous from a distance, now seemed large enough for Cal to put his fist into. But the eye, though within reach, was guarded by a heavy overhanging ridge of bone and skin; he was sure that if he struck at it the eye would blink shut, and he would smash his hand against that protection painfully. The ear indentation did not even penetrate the head; skin covered the canal just inside the depression. Yes, the dinosaur was well protected.

 

      Still, Tyrann could hear well enough. Cal leaned toward the head until only inches separated his face from the skin of the monster. The rank odor made him want to gag, and he could see body parasites in the folds.

 

      'Boo!' he yelled.

 

      The dinosaur jumped.

 

      Cal was off and away, sprinting again for the copse of sorted firs. Tyrann recovered in a moment, merely startled the unexpected noise, but too late. A jump reaction, in a creature of that size, was a matter of seconds from start to finish. The prey had won another round.

 

      The firs were not large, but were close together and thickly spoked. The proximity of the trees served to break off useless lower limbs - but many of the stubs were jammed into neighboring trunks, forming rungs. Cal scraped himself getting through them, but was grateful for their protection. Tyrann had to crash through headlong, and that was noisy, painful and time-consuming. Cal was able to catch his breath again as he slowed to a walk and scramble, threading past the worst of the maze.

 

      But it was another brief respite. Tyrann could knock aside those slender trees and bulldoze them down, and was doing so. The stand was not as extensive as Cal had hoped; a few minutes would see little besides cordwood here. And the dinosaur, stung by repeated jabs of fir spokes, was beginning to grow perturbed.

 

      Beyond this was palm-dotted prairie. That was sure victory for Tyrann.

 

      Except - there was a herd of Triceratops in sight, lazing in the shadow of the trees and browsing on the fronds. If he were able to play one species off against the other -

 

      Cal ran out toward the herd. A bull winded him and looked up, a morsel of palm stalk projecting from his tremendous beak. Then the Tricer spotted the carnosaur behind. Why the herd hadn't noticed the intrusion before, Cal could not say. Perhaps they had been aware of Tyrann right along, but had known he was after other prey and therefore no immediate threat to the herd. That, combined with the discomfort of having to walk through the sun to find other shade, must have kept them where they were. It was a complacency that armored,, brutes of this magnitude could afford - but no lesser creatures!!

 

      By running at the herd, however, Cal was luring Tyrann too close. The bull gave out an oddly regressive hiss, and suddenly there was motion elsewhere. The adult Tricers bullied their young into a confined area adjacent to the trunk of largest palm, then turned about and formed a ring outside, just at the fringe of the shade, armored heads pointing out. It was a formidable phalanx, executed with military dispatch.

 

      Cal was daunted himself. These were tremendous animals and dangerous. Those beaks, intended for slicing through palm wood, could as readily amputate his limbs; and as for the horns ... ! But he had no choice. Tyrann was closing the gap again, and there was no other cover. He ran at the defensive circle of behemoths.

 

      The nearest bull didn't like it. He hissed his challenge again and charged out of the pack. Sunlight glinted from his polished horns. The adjacent bulls rocked over to fill the gap, keeping the circle tight. Cal, per force, brought up short. No living animal ever resembled a tank more than Triceratops. Then he used the trick applied earlier to Tyrann, and jumped to the side.

 

      Almost eight tons of armored flesh thudded by. The Tricer was not as large as Tyrann, but was more solidly built. Its body, exclusive of the tail, was twenty feet long, the head taking up about a third of it. Two devastating horns jutted above the eyes and a third, shorter but thicker, perched on the broad beak. Behind the head was a tremendous bony shield large enough for a man to ride on. The astonishing jaw muscles anchored to this, making even Tyrann's face seem flabby in comparison. There was more bone and muscle on Tricer's head than in the entire body of most other creatures. The skin of the rest of the torso, though technically unarmored, was ribbed like the hide of a crocodile, and Cal was sure it was just as tough.

 

      Now Tricer confronted Tyrann - a situation neither had sought. Tyrann tried to skirt around the bull to get at Cal, but Tricer would not permit an approach near the herd. To it, the small mammal was an annoyance - but the carnosaur was a threat.

 

      And so they came to unwilling battle, these two giants of the age of reptiles. The one would not relinquish his chase; the herd would not permit passage.

 

      Tyrann, goaded to fury by the unreasonable interference of bull, roared and gestured: an impressive spectacle. Tricer merely waited, the three fierce horns focused on the enemy. Tyrann skittered to the side, seeking a vulnerable point beyond horn and shield. Tricer whirled with surprising finesse, the neck muscles flexing hugely, and gored him in the thigh. Tyrann screamed and bit at the briefly exposed rump. The teeth sank in, but Tricer whirled again, the three horns swinging about like the machine-gun turret of the tank he resembled, and the hold was broken. Cal observed that the broad bony shield did double duty: the neck musculature also anchored to it. Just as a flying bird needed a strong keelbone to brace the flying muscles, so Tricer needed that shield to whip his massive head about. What an engine of defense!

 

      Blood speckled each combatant, but inhibited neither. Tyrann did not take lightly to being balked, but Tricer would not give way,!

 

      Then a second bull came out, and Tyrann backed off hastily. Two trios of horns could destroy him. But this one was after Cal, and the man had to flee even more precipitously. Apparently the herbivores had decided that he was too much trouble to entertain. Or they had realized that Tyrann would not leave until the mammal did.