The crash of landing, the surge and jolt of the waves close to the surface, all were behind them now as the two SEALs drove downward on strong, steady kicks of their borrowed BGA fins. Both men held underwater lights, but the water was so laden with silt that the beams, dazzling bright where they were reflected by the countless drifting particles, could not penetrate more than about ten feet. No matter. The massive southeastern pylon of Bouddica Alpha was vaguely sensed as a massive cliff face rising slowly past on their right, and the A-bomb, traveling more or less straight down, would have landed about thirty yards southeast of the pylon’s base. They would dive to the bottom, take their bearings, and then begin a simple search pattern, working out southeast from the pylon.

Passing 125 feet. Almost halfway down. The pressure was up to almost four atmospheres now.

At sea level, in the open air, the atmosphere exerts a steady pressure of just over fourteen pounds per square inch, a condition, referred to as “one atmosphere,” caused by the sheer weight of all of the air extending from that square inch of skin clear to the top of the Earth’s atmosphere.

For every thirty-three feet of depth beneath the surface, another one atmosphere of pressure is added, thanks to the extra weight of the water overhead. At 125 feet, the pressure was equal to 3.8 atmospheres—or fifty-three pounds of pressure against each square inch of Murdock’s body.

No wonder even the double steel hulls of submarines quickly reached a point vividly referred to as their crush depths after they’d descended to a depth of a scant few thousand feet.

One hundred eighty feet, and a pressure of 5.7 atmospheres—eighty pounds per square inch. Murdock felt no differently, of course, since the external pressure was balanced from within; his regulator was feeding him heliox at higher and higher pressures to compensate.

Any uneasiness, any queasiness he felt was purely psychological.

It was cold too. His neoprene dry suit was designed to keep a warming layer of air between inner and outer layers, but no system is perfect. He suspected that water was working its way through to the inside.

No problem. He’d endured much worse than this in training. He kept going down. “Razor? You still with me?” His voice sounded exactly like the quacking of a duck, and he had to suppress a laugh.

“I’m here, L-T,” Roselli chirped and quacked. “Great voice.”

“Yeah. We should sing soprano.”

Two hundred ten feet. Over ninety-three pounds per square inch. Getting close now. Must be. The chill was fierce, threatening to set him to trembling. He checked his watch and was surprised to see that they’d only been in the water about four minutes. A descent rate of fifty-and-some feet per minute? A foot a second. Yeah. That wasn’t bad.

Two hundred thirty feet. The bottom appeared like a fuzzy white wall anchored in the round shaft of his light. Roselli’s light flashed across the mud to the left as Murdock swung his feet beneath him and touched down in a tiny, silent explosion of silt.

“Falcon, Falcon,” he chirped. “Do you read me? Over.”

No reply. They must not be close enough to the radio pickups. Or else pressure or cold or a million other things that could go wrong had sabotaged the radio. Never mind. Where was the pylon? There . . . a looming, moss-covered pillar, a fuzzy cliff in the night. Rising, he swam closer. That wasn’t moss after all, but fine tendrils of silt. Matter acted in strange ways at extreme depth. Carefully, Murdock gave the line he was still clutching in his left hand a tug, freeing up some more play. From here, there was no sign at all of the surface, no sign of anything at all save the two divers and their tiny bubble of light. There were no fish, no sign of any other life at all.

Murdock checked his compass. “That way.”

“Roger.”

Together, they started swimming toward where the bomb ought to be, each stroke of their flippers stirring up a fresh swirl of silt. Murdock was aware of strange objects looming out of the darkness all around, however, and was beginning to wonder if this search would be as easy as he’d thought it might be while he’d still been relatively safe and warm on the surface. Pipelines ran across the bottom in every direction, while storage tanks and less identifiable pieces of gear were scattered across the sea floor like a child giant’s toys. Before the dive he’d been wondering if a metal detector or a hand-held sonar might be useful, but had decided against them for reasons of time. Now he realized he’d made the right choice; both would have been useless here.

The question was whether even a careful search by Mark I eyeball would be any better.

Odd. It was growing lighter.

At first, Murdock thought he was suffering from nitrogen narcosis . . . but that shouldn’t be possible on heliox. Something was affecting his brain, however, because suddenly the entire landscape was lit as brightly as day, no matter which way he pointed his light.

He looked up . . .

. . . and stared into the dazzle of a ring of spotlights. Murdock’s first thought was that he was looking at some strange kind of sea monster; there were extraordinary creatures in the deeps, creatures that could produce their own light . . . but then reality reasserted itself and he realized he was looking at the North Korean minisub. It was shaped something like a blunt-nosed, stubby torpedo, with the underside of its nose recessed beneath a massive snout. Powerful spotlights circled a row of three windows. To either side, a manipulator arm was extended as though to reach out and snatch, each tipped with grasping, titanium claws.

“Watch it, Razor!” he called. “Minisub, twelve o’clock!”

They broke left and right and the claws missed them, the submarine rushing past just overhead, buffeting them in its wake and prop wash. The noise of its twin screws was a high-pitched chirring, audible above the whine of its motors.

The sub swung to port, chasing Roselli. Murdock’s mind was racing. A weapon! He needed a weapon! But there was nothing but his diver’s knife, useless against . . .

Or was it? He also had the length of nylon line, still trailing down from the surface. Like every man in love with the sea, Murdock had spent his share of time in small boats. He’d once spent a very unhappy afternoon adrift on a lake, trying to cut away a length of fishing line that had become snarled around the shaft of his speedboat’s propeller.

Jerking his diver’s knife from its sheath, he measured off several arms’ lengths of line, then cut it. He was also cutting off the shackle, of course, but there was no time to worry about that now. Leaving the main line adrift, he took his ten-foot length and advanced on the submarine, the hunter in pursuit of his prey.

He could see Roselli a few yards ahead of the monster, backing away. “Watch it, Razor!” he called. “Watch your back.”

He didn’t think Roselli heard him. The other SEAL backed squarely into the unyielding wall of a large undersea storage tank, his heliox tanks giving a metallic ring easily heard through the water. He tried to turn, tried to swim clear . . . and the submarine’s arms descended. One claw clasped around his arm; the other groped for his face.

Murdock reached the minisub’s stern a moment later, straddling the horizontal wing that mounted two propeller cowls, one to the left, the other to the right. He fed the end of the line through the starboard cowling. For a moment, the prop wasn’t turning, and he kept stuffing the line through the narrow space at the front of the shroud.

Then the engine switched on, the line was reeled in . . . and with a grating squeak, the propeller stopped.

The port-side prop spun furiously, spinning the sub like a top. Murdock was knocked clear. Roselli, he saw, was free of the thing’s grasp, but hurt, clutching his arm as a cloud of dark blood spilled into the water. The sub kept turning, swinging about to face Murdock, arms descending. Whoever was piloting that thing—it had to be Chun—was good. Even on one screw, she was keeping the sub trim and balanced, pivoting the bow left and right as she pursued her next victim. The sub, Murdock saw, was equipped with small, high-pressure thrusters. Even with one prop out, she could still maneuver that thing.

He ducked left, avoiding a stroke from one snapping claw. If he could foul the second propeller . . . but he would have to swing back and find the dangling line again, and he didn’t think that Chun was going to give him the luxury of time. He backpedaled, and the sub advanced. The lights were blinding, almost mesmerizing. Each time Murdock tried to shift left or right, up or down, the sub matched him, coming closer. Possibly he could get inside the reach of its arms and cling to the hull, but then what? A fast ascent might kill him; at least it would keep him away from the nuke, which had to be Chun’s plan.

The lady was going to stay here, taking on all comers, until the damned thing exploded.

Murdock was just about out of options. If he could find something lying in the mud, a piece of chain, a length of pipe, anything, he might have a chance. As it was . . .

The whale shape came in from the left, arrowing straight toward the submarine’s starboard side. Its blunt nose struck just below the conning tower, a ringing crack that seemed to echo off the seafloor and the BGA bottom structures nearby.

The bus! Johnson and the bus! The crazy idiot had disobeyed orders and brought the bus down, swinging in at top speed and ramming the North Korean sub.

He felt weak.

Somehow, he managed to stay focused. The submarine was in trouble; he could hear a thin, high wailing coming from it, could see the stream of bubbles trailing from a nasty-looking dent beneath the conning tower. The pressure hull had cracked; water must be blasting into the interior, propelled by a pressure of 120 pounds per square inch. The bubble stream grew bigger, more insistent. The sub’s interior space would be filling with water now, squeezing the air inside to a fraction of its former volume.

As the sub slowly settled toward the bottom, motors and thrusters silent now, he wondered if Chun was still alive.

No. She couldn’t be. Not after the near-explosive compression of the tiny sub’s cabin.

It took nearly ten more minutes to find the bomb, half buried in the silt about where they’d expected to find it. It took another ten minutes to find the cut-off length of line; by that time, the cold was penetrating Murdock’s dry suit so badly that he was shaking violently. It was all he could do to drag himself onto the blunt, upper end of the bomb, thread the nylon through the shackle eye, and tie a knot. His first attempts failed . . . but he kept at it, and at it. . . . It would have been impossible without Johnson, who held the SDV steady to keep its forward light on the job; Murdock could never have tied that knot in total darkness.

He was having trouble breathing, and the ends of the knot kept slipping from numb and unresponsive fingers. “Damn it, Johnson, let’s have some light here.”

“I’ve got the light full on you, L-T.” The squeaking voice was almost impossible to understand.

“Say . . . again. Say . . . again. You’re breaking up.” Damn! He almost had it that time! Angrily, he stopped and pulled off his gloves, feeling the icy water flood up his arms. If he could finish the knot before he lost all sensation in his fingers entirely . . .

It took him a long time to realize that the problem was not with Johnson’s light . . . but with his brain.

Somehow, he managed not to pass out until after the knot was tied, a good sturdy fisherman’s bend that any Navy boatswain’s mate would have been proud of.