Chapter 55

While Joe dug in to fight a pitched battle, Kurt and Kai swam across the bay, heading for the dock and surfacing underneath it.

Kai looked around until she felt called in one direction. “This way.”

She let go of the wall and began swimming underneath the length of the dock. Kurt followed, realizing he’d have to trust in the Gray Witch from this point forward. They came to an inlet where water was being drawn into a large-diameter concrete pipe.

A huge grate over the inlet was covered in multiple filters.

“TAU’s cooling system,” Kurt said. “This is where they draw the water in.”

Without explanation, the clamps holding it in place released and it swung open.

“We go in,” Kai said.

They slipped inside. The water filled only half of the tunnel, leaving a two-foot gap of air at the top. That would change as the tunnel angled down toward the lower levels, where the servers were housed, but for now it let them float along with ease.

The current was mild, though based on the way these cooling systems worked Kurt knew it would accelerate either through the use of pumps or smaller-diameter pipes. That would be a problem for them, almost certainly fatal either way, if they didn’t exit the tunnel before it happened. Still, he allowed himself to be pulled inside. If it was Priya who’d unlocked the gate, then she’d have a plan to help them once they got inside. And if instead they were actually being lured to their deaths by TAU, there would be little he could do at this point other than tip his cap to the mad and sadistic machine.

As they floated along, Kurt’s eyes adjusted to the light. Every hundred feet or so a tiny cube in a protected case cast a minor glow from the ceiling. Kurt noticed wiring and a bundle of shielded cables. So far he hadn’t seen anything resembling an exit, but there had to be a way for maintenance crews to get in and out of the tunnel.

The tunnel bent to the right and the sound of turbulence could be heard. Peering as far ahead as he could, Kurt saw a foamy area up ahead. He recognized the sound of air rushing up and bursting free. This was the down shaft that would lead to the various server units. Trapped air was shooting back up as the flow became liquid only.

Kurt felt Kai gripping his hand.

“It’s okay,” Kurt said. “She’s going to have a plan. Reach out to her.”

Kai shook her head. “I can’t feel her. Not in here.”

Kurt didn’t like the sound of that. He used his feet against the bottom of the tunnel to slow their progress. He began dragging his fingers along the side of the wall, feeling for a handhold.

Kai began to fight the current. “We should go back.”

There was no going back. Not even against this mild current. The water was simply too high. The bottom of the pipe too slick. Best they could do was fight and delay, but they were still moving forward.

There had to be a maintenance hatch or ventilation shaft somewhere. Kurt looked around, even as he tried to brace himself against the pull of the water. Up ahead, one of the lights started blinking.

“Let’s hope that’s not bad wiring,” he said, releasing the brakes.

The current pulled them smoothly once again. As they closed in on the blinking light, a ladder appeared out of the gloom. It hugged the left-hand side of the pipe and went up into a gap in the top.

Kurt grabbed it and pulled Kai toward him. In a moment they were both clinging to the rungs.

“Now what?” Kai asked.

Kurt looked up. Somewhere up above there would be a hatch or a manhole cover or something similar. “Time to lose the tanks and fins,” he said, shedding his harness and clipping it around the ladder so it wouldn’t float away.

Kai followed suit and then climbed onto the ladder.

“Give me your backpack,” Kurt said.

She loosened the straps, sliding one arm out and then the other. Kurt took it from her as she climbed the ladder into the darkness.

“There’s a hatch,” she said, “but it’s stuck.”

“Whatever you do, don’t knock,” Kurt said. He figured Priya would open it remotely, as she’d done with the exterior grate. He hoped she’d give him another minute or two, as he was busy tinkering with the explosives in their backpacks.

“It’s opening,” Kai said.

Kurt could hear the metal hatch sliding out of place. A bit of extra light poured through, just enough to help him set a timer on the last charge he had been fiddling with. The charge was a tiny one. He taped it to the rung of the ladder to which the backpacks and dive gear had been secured.

If placed correctly, the small charge would split the metal rung in two without harming the backpacks, which would float away, drop down into TAU’s cooling system, and detonate somewhere underneath the compound.

Kurt had to guess at a lot of variables, including the flow of the current, the distance to the main part of the cooling tunnels, and how far beneath the island TAU’s servers were hidden. But he had one thing going for him that would help gloss over any mistakes. Forty pounds of octanitrocubane going off in a tight space would create a devastating pressure surge in all directions. The water would magnify that surge. As long as the explosives were still in the tunnel when they blew, Vaughn’s compound would collapse like an imploding bubble.

With the small charge set, Kurt pulled one last stick of explosives from his pack and went up the ladder. Ten feet above, he emerged into a maintenance tunnel filled with power conduits, water pipes, and a continuous string of the tiny white lights. Some of which were already blinking.