The hands vanished and the water churned slightly as the two finned away. Mercer pulled Lauren’s Rolex from his pocket and noted the time. Forty-five minutes, she’d said. They’d be back up at seven-eighteen.
The sensation was like falling into a bottomless bathtub because the water was blood warm. Lauren twisted in liquid space and tucked her knees to her chest to slip on her flippers before adding air to the buoyancy compensator. She and Vic found their equilibrium at the same time and both slid toward the surface to give Mercer a signal that they were all right. She bled a little air from the vest, allowing her to drop back into the void. They leveled off at forty feet, deep enough for much of their exhausted breaths to dissipate. She immediately equalized the pressure in her ears and behind her face mask. Through the murky water, Lauren could feel the throbbing engine and thrashing propeller of the freighter passing abeam of them.
Because she was used to ocean diving, it took her a few moments to get used to the difference in buoyancy the freshwater gave her and its silty taste. Visibility was pretty bad, maybe twenty feet, but would give her enough warning if there was anything in the water with them. There was little current this far from the locks, yet Lauren was prepared for the suck of water once one of the chambers began to fill.
Together, she and Vic began swimming in easy strokes toward the lock.
Her PADI instructor once told her that scuba was the sport for the lazy. Do nothing fast and don’t waste energy you might need later. It was advice she’d never forgotten.
Using just the strength in her supple legs, she kicked through the milky emerald water toward the distant concrete structure. Vic stayed at her side. Above them, the setting sun had turned the surface into a distant plane of crimson mercury. Below lurked an impenetrable gloom.
Mercer’s assurance that he was okay rang in her mind. She wouldn’t have gone in the water if she didn’t believe him. He was up to this mission, yet she still harbored a lingering doubt. He had been damaged in that torture chamber in some way he refused to acknowledge. It was a male thing, she felt, the unwillingness to admit pain. She’d seen it in her father, her brothers, and all during her military career, especially in Kosovo. Like most men, Mercer would stupidly spend days or weeks working it out himself rather than save time by talking.
Lauren wanted to help him. She remembered him talking about his childhood in Africa and knew he was capable of expressing his feelings. If she could—
Focus, damnit, she admonished herself, concentrating on her breathing. She had her own priorities right now.
After ten minutes of swimming, a shadow formed in front of her and Vic. Like coming across a sunken building, they approached huge walls of cement that quickly filled their vision. The front of the twin locks.
Vic jerked a thumb downward. Lauren nodded and the two sank farther into the abyss, coming up on the bottom at fifty-five feet. The floor of the canal was barren stone, swept clean by the remorseless tidal action of the locks filling and draining. It looked like a desert. Not a piece of trash, leaf, or stick in sight. The bottom of the locks sat on a massive concrete foundation ten feet above them. The steel doors were like those guarding a giant’s castle, utterly impregnable.
Flanking each set of doors were culverts formed within the cement, each bigger than a subway tunnel. These eighteen-foot-diameter pipes were the inlets through which water entered the lock. Feeding off them inside the lock’s walls were fourteen evenly spaced branches, each large enough to accommodate an automobile. These cross-passages stretched under the chambers themselves, and from them a total of seventy separate stem valves rose into the floor of the lock to evenly distribute the flow of water. The apertures in the lock’s floor in which the stem valves sat were ostensibly the smallest component of the whole mechanism and yet each was four feet square. All this piping could fill a 110,000-square-foot lock at a rate of two feet a minute. The billions of gallons that drain from the canal each year are replaced by seven feet of annual rainfall recharging Lake Gatun through the Chagres and other rivers.
Lauren hung suspended, mesmerized by the scale of what she was seeing. Age had darkened the concrete to a dull black, but the main feeder pipes were darker still, somehow malevolent, like haunted caves from a child’s nightmare. Despite the warm water, a chill ran up her spine and she whirled around, certain she was being watched.
Vic signed if she was all right and she acknowledged that she was. Her heart refused to slow and her breathing had accelerated. Again, she looked around. This time she caught a flicker of movement. Something was out there, another patch of darkness that wavered just beyond her view. She strained to see it, beaming her dive light in its direction. Nothing.
Come on, girl. Get a grip.
And then it came, resolving out of the murk, driving at them with the speed of a torpedo. Lauren got a brief impression of something silver before it was upon them. Even with the distortion of the water, it was at least eight feet long, powerful. She screamed into her mouthpiece, choking as she took a mouthful of water.
Vic’s hand lunged out to grip her shoulder, the touch enough to calm her. She blinked and realized their attacker was one of the tarpon that regularly got caught in the canal. The monstrous fish with its underslung jaw broke off its investigation and carved a tight circle around them to return to its hunt for a way out of the freshwater trap.
Lauren gave Tomanovic an embarrassed shrug. She readjusted the equipment that had shifted during her violent thrashing, making sure to note her air consumption. She compared her gauge to his. They were about even.
She looked back at the doors above them. It was hard to believe that something that large could move, yet they began to swing outward on hinges that weighed nearly twenty tons apiece. She could feel the movement of water as newly installed hydraulic rams forced them apart. A freighter or tanker would be drawn out from within the lock by the mules in just a few minutes. After that the doors would reseal themselves and the water within the chamber would drain into Miraflores Lake to lower the level for the next vessel coming up the thirty-foot stair.
Once that next ship was secured inside the lock and the doors closed, more than eight million gallons of water would be sucked through the intake pipes to raise it up to the level of the Gaillard Cut. The rush would create a surge more powerful than the worst rip current, a force that neither Lauren nor Vic could ever hope to fight. They’d likely be crushed within the labyrinth of tunnels under the lock and their corpses would eventually flush through the system like so much trash.
It was time to find the submersible.
Keeping the dive lights angled downward so they wouldn’t show to guards and workers above, they began scouring the bottom of the canal, looking for anything out of place, some piece of evidence that ships were being intentionally diverted by something kept here at Pedro Miguel.
If she and Vic couldn’t find evidence, they’d all have to rethink their theory about what Liu Yousheng and Hatcherly were trying to accomplish in Panama. Maybe this really was an elaborate smuggling scheme that had nothing to do with the canal. It could be that was what was bothering Mercer, Lauren realized. The idea that his theory could be tossed out the window and he wasn’t in on the investigation. From their first night on the River of Ruin, she knew he was a man who valued his self-reliance and she doubted he’d accept someone else’s conclusions without investigating on his own.
That wasn’t a male thing, she thought. That was a scientist thing.