KEEP LOOKING, Christine Vale commanded herself. It’s got to be here somewhere. You just have to find it.

Vale had never been fond of underwater operations. Working underwater was a lot like working in space. All the consequences were reversed, of course—crushing pressure versus vacuum, freezing instead of instantly boiling, implosion rather than explosion, flooding as opposed to venting—but they were still just as deadly, and the environment just as unforgiving. One other thing they had in common was the awkwardness of movement. Each milieu was alien to human physiology in its own way, and Vale, left to her own devices, would avoid them both.

But here she was, now with less than an hour—give or take a few minutes—until the start of the Klingon invasion, looking for the firebase’s waste-exhaust port, which refused to be found.

The meter-wide venting aperture was almost certain to be located on the ocean floor, within less than a fifty-meter radius of the entrance tower. Unfortunately, that meant Vale now had to search an area of nearly eight square kilometers, one meter at a time, while swimming in circles. Her tricorder also wasn’t proving to be of much use. The port must be camouflaged, she reasoned.

Spitale’s voice crackled over the com. “Spitale to Vale,” she said. “Ready to go here.”

“Acknowledged,” Vale said. Spitale had been burdened with the team’s second-hardest assignment: deducing a structural weak spot in the entrance tower’s outer shell that, if ruptured, would cause rapid flooding of the entire base but also leave the Tezwans a path of escape to the docked submarine. It was a testament to the young woman’s intelligence that within a matter of minutes she had found an exterior hatch used by maintenance robots and determined it to be this base’s Achilles’ heel.

The ocean floor was rocky and barren, permanently sequestered from daylight. No vegetation grew down here. Vale’s only company as she swam in lonely, ever-widening circles around the base were roaming crustaceans, skittish bottom-feeders, and a single luminescent aquatic predator that had wearied of shadowing her after its third zap from her phaser, which the Enterprise’s team of weapons experts had specially modified for underwater use.

Another transmission scratched over the speaker in her helmet. “Sakrysta to Vale.”

“Go ahead,” Vale said, hoping nothing had gone wrong. Sakrysta and Fillion’s mission was to sabotage the submarine’s weapons and primary propulsion. Once Delta Team started their assault, they couldn’t let the submarine crew shoot at them or move out of jamming range to alert the planet’s military.

“We’re in position,” Sakrysta said.

“Glad to hear it,” Vale said. “I’m still—” She was about to apologize for her delay in finding the elusive waste vent when a chugging surge resounded through the depths. Turning to look behind her, she saw a jet of air bubbles and discolored fluid surging up, seemingly out of solid rock. She locked her tricorder onto the frothing plume, which dwindled and vanished a few moments later. She keyed her com. “Stand by.”

Following the tricorder’s target lock, she found herself floating above an expertly disguised metallic iris. Its outer surface was composed of natural composites from the surrounding sea bed, but the durable metal inside defied her tricorder’s attempts to scan it. On a hunch, she chipped away a small chunk of the outer coating, then fired a low-power phaser burst at the exposed metal underneath. The phaser beam reflected off the metal like a flashlight beam off a mirror. The tricorder still couldn’t read the metal, but it detected a momentary surge of several types of rare particles.

Chimerium, Vale realized. The only place to get this stuff is Sarindar. And only the Federation has the right to export it from the Nalori Republic. Starfleet might not have put this stuff here, but we definitely built it.

She increased the power of her phaser and swiftly burned a hole through the ocean floor right next to the phaser-proof iris, cutting at a sharp angle into the shaft beneath. She was gambling that because chimerium was so rare and difficult to work with, whoever built this facility would not have used it for something so mundane as a waste-exhaust shaft. Her hunch proved correct, and her phaser beam easily sliced a short, twenty-centimeter-wide channel directly into the exhaust shaft.

She holstered her rifle and carefully removed two ultritium charges from her chest pack. “Vale to Delta Team,” she said, keying her com. “I’m in position. Everybody confirm.”

“Spitale, ready.”

“Sakrysta, set.”

“Fillion, good to go.”

“Acknowledged,” Vale said. “Sakrysta and Fillion, you’re first. Go!”

The two explosions sounded much closer than Vale knew they were, and she recalled that water was superior to air as a medium for propagating sound waves.

“Spitale,” Vale said, “go!” Moments later, another rumble of watery thunder shook the ocean depths. She armed the fuses on her ultritium charges and released them into the shaft. She turned and swam away from the exhaust port as quickly as she was able. Moments later the cacophonous boom roared behind her, sending up a fiery rush of gas that dislodged the chimerium iris, which then sank into the ocean floor as the shaft imploded beneath it.

“Vale to Delta Team, sound off.”

“Sakrysta here.”

“Fillion here.”

“Spitale here.”

So far so good, Vale congratulated herself. “Sakrysta, rig the airlock with a light charge,” she said, swimming with broad, strong strokes and kicks back to the now-flooding base. “As soon as the base personnel are out, blow the airlock so they don’t come back—but don’t compromise the sub itself.”

“Aye, sir,” Sakrysta said. “I’m on it.”

Vale checked her chronometer. If the Klingon fleet was punctual, the invasion would begin in fifty-two minutes. Her best guess was that it would take at least thirty minutes to flood the entire base and cut off the airlock access. That would leave twenty-two minutes to blast their way in, find the target points, plant the charges, help disable the Tezwan fleet, and reach minimum safe distance from which to blow up the base.

She rolled her eyes in mute protest. Piece of cake.