He took the laptop, placed it on the rough surface of the helipad and shoved it toward Jinn.

Jinn stared at it but did nothing more.

Zarrina seemed nervous. She bit her lip, hesitated and then spoke. “Type in the code,” she said to Jinn.

Behind them the first two airships were ready, their pods inflated to full volume, their fans powering up. The third was right behind them.

“What’s the word?” Kurt asked Marchetti without turning.

“If we deploy the air anchors and get up to speed before we go off the edge, I think we can carry eleven,” Marchetti said. “I think.”

“Put twelve on each.”

“But I’m not sure—”

Kurt silenced him with a glance and looked Marchetti in the eye. “I’m going to need your help,” he said, handing him one of the small radios. “Now, what’s the word?”

“Twelve,” Marchetti said. “We can do twelve … I hope.”

“That’s only thirty-six,” Gamay said, calculating quickly. “There are thirty-seven of us.”

Jinn smiled at the numbers. “I suppose someone is staying behind to die.”

Kurt replied without blinking. “I am.”

CHAPTER 56

JOE WENT INTO THE WATER OF LAKE NASSER IN AN OLD-school diving getup. It wasn’t exactly the old brass helmeted, Mark V salvage gear the U.S. had stopped using shortly after World War Two, but it came close.

A thirty-pound helmet of stainless steel fit over his head and onto the shoulders of the suit. A fifty-pound belt strapped around his waist and heavy, weighted boots made taking a few steps a Frankenstein-like walk.

An air hose, a steel cable and a high-pressure line for pumping the Ultra-Set were attached to the shoulder mounts. They made him feel like a marionette, but once he hit the water Joe was glad for every ounce of weight and the security of the steel cable.

The weight kept him balanced in the swirling current. The cable, which was attached to a dive boat above him, was the only way to ascend with so much weight on. If it snapped, he would sink to the bottom like a stone and probably be excavated in a thousand years or so, only to baffle future archaeologists.

Joe had no desire to be part of the Valley of the Dead. All he wanted to do was to stop the dam from being washed away.

If he and the supervisor were right, the main breach was containable, and while disastrous, especially for those close to the dam, it was not cataclysmic. It would widen, perhaps to the full width of the dam, but the clay core and the gentle slope of the structure would keep it from eroding any deeper.

Eventually, like water spilling out of an overflowing bathtub, the water level in the lake would drop to a level matching the depth of the breach and the flow would slow and eventually stop.

But if the microbots were burrowing into the clay core from the tunnel, the incredible pressure of the water would weaken the core itself. It would eventually fail. A bigger, deeper, more jagged breach would form and there would be nothing to keep the dam from total collapse.

As Joe’s feet touched down on the sloping surface below, the speaker in his helmet crackled.

“Diver, can you hear me?” It was the supervisor. He was up above, risking his life on the dive boat, along with the major and another technician.

“Barely,” Joe said.

“We’re just over a hundred feet from the breach,” the supervisor said. “It continues to widen at a rate of three feet per minute. You have less than thirty minutes to find the entry point or we’ll be caught in the outflow and dragged over the top of the dam.”

Joe figured differently. Within twenty minutes, the breach would be too close for either he or the boat to fight the effects of the current.

“I never wanted to go over the falls in a barrel,” he said, “and I still don’t. Let’s get this done. Start pumping the dye.”

A pump above on the dive boat began to rumble, and a secondary line attached to the Ultra-Set hose pressurized.

Down below, a high-pressure spray of fluorescent orange particles began to jet out of the hose. Joe switched on a black light attached to his helmet. The particles lit up like fireflies as they swirled in the murky water washing slowly to Joe’s left.

At the limit of his vision, Joe saw them quicken and speed toward the surface headed for the breach in the dam. That was the death zone. When that high-speed current reached him, there would be no escape.

Joe moved across the wall, hopping side to side like a spaceman on the moon. He washed the dye up and back across the area where the tunnel’s entry point was suspected to be. It flowed oddly over the uneven surface of the boulders and stones.

Ten minutes and twenty swaths later, they were still without luck.

“We need to go deeper,” Joe said. “Pull us back away from the dam.”

“The farther out we go, the stronger the drag from the break in the dam,” the supervisor said.

“It’s either that or call it a day,” Joe said.

“Hang on.”

A second later Joe felt the steel cable lift him off the slope. From there he was dragged backward perhaps another thirty or forty feet and dropped down again.

As he landed, he could feel the sideways pull of the current tugging at his feet. He pulled the trigger on the fluorescent spray and saw it catch in the crosscurrent to the left. At first it looked no different than the other marking attempts, but this time Joe noticed an eddy swirling in the pattern.

“Ten feet left,” he said.

“Closer to the breach?”

“Yes.”

Joe began to walk. High above, the dive boat moved with him. He pulled the trigger again, aiming the reflective stream of particles right at the center of the eddy.

The glowing particles swirled and the majority of the spray was sucked into a gap between two railroad tie–sized beams of concrete, vanishing in a blink like fish disappearing into coral at the sight of a predator. It happened so quick, Joe had to trigger a second burst of the spray just to be sure.

“I’ve found it,” he said. “The gap is between two concrete pylons in the riprap. I can feel the suction from it.”

As Joe got closer, he felt himself being pulled into the gap. He could see sand and gravel disappearing from around the edges of the beams. A crater was widening beneath them, he could see what looked like a twenty-inch-diameter hole.

He wedged a foot against one of the concrete beams to keep from getting sucked in. As much as he wanted to block the hole, he personally didn’t want to be the plug.

“I’m ready for the mud.”

“Mud?”

“The Ultra-Set,” Joe clarified, awkwardly holding himself back.

“Starting the pumps now,” the supervisor said.

Careful to maintain his balance, Joe managed to jam the front end of the hose into the opening. As the pressure came up, he pulled the trigger.

The Ultra-Set began flowing out at high pressure, some of it escaped into the water, looking like magenta-colored whipped cream as it expanded and hardened. Most of it funneled into the breach drawn down by the suction of the unwanted tunnel.

“How much does this stuff expand?” Joe asked.

“Twenty times its original volume,” the supervisor said. “And then it hardens.”

Joe hoped it would. And if there were any microbots left in the core, trying to widen and expand the breach, he hoped they would be caught in it and frozen in place like insects in amber.

The current tugged him to the left and he heard the rumble of the falls over the motor of the boat and the pump above him.

“Anything?” Joe asked after about thirty seconds.

“Control reports orange dye from the lower geyser,” the supervisor said. “The water flow is unchanged.”

“How much of this stuff do we have?”

“The tank holds five hundred gallons,” the supervisor told him. “It pumps two hundred gallons per minute.”