Joe donned a similar pair, and the two men began hiking.

Ninety minutes later they crested the latest in a series of endless dunes. As they reached the top, they caught wind of a helicopter approaching from the south.

Scanning around for the source of the noise, Kurt spotted a flashing red beacon in the sky. It looked to be no more than two or three miles away, cruising at five hundred feet and headed straight for them.

“Get down,” Kurt said, dropping flat to the ground and trying to burrow in the sand like a sidewinder.

Joe did the same, and in a moment they were just about covered up to their necks. Despite this camouflage, the helicopter continued toward them, never deviating or changing course.

“This looks bad,” Joe whispered.

Kurt’s hand found the holster on his hip and the .50 caliber Bowen revolver inside it. The gun was a cannon, though it wouldn’t do much good against a helicopter unless he made a couple of perfectly lucky shots.

He locked onto the red light. A dimmer green light glowed on the other side. If it came to it, Kurt would aim right between the two and empty the cylinder in hopes of hitting something vital.

He heard Joe unlatch his own pistol, likely planning to do the same, when a thought occurred to him: if they’d been spotted and the copter sent out to hunt them down, why wasn’t it blacked out?

“Nice of them to leave their nav lights on for us to aim at,” he said.

“You think they made a mistake?”

The helicopter continued toward them, now only a quarter mile away and still descending but also changing course.

“I guess we’re about to find out.”

The helicopter thundered past, two hundred feet above them and a couple hundred yards to the west.

Kurt watched it pass and tracked its course. Seeing no other aircraft trailing it, he pulled out of the sand and raced after it. He made it to the bottom of the dune and clambered up the top of the next one, throwing himself flat against the sand as he reached the peak.

Joe hit the ground next to him. Ahead of them the helicopter slowed to a hover, descending toward a dark shape that rose from the desert floor like a ship on the sea.

A band of low-intensity lights came on, marking a circle on the top of the “ship.” The helicopter adjusted, pivoting slowly and then settling onto the rocky bluff.

“Looks like we’ve found the compound,” Kurt said.

“We’re not the only ones,” Joe replied.

Lights could be seen approaching from the southwest. It looked like a small convoy, maybe eight or nine vehicles. It was hard to count the headlights with all the dust they were kicking up.

“I thought Dirk said this place didn’t get much traffic?”

“Apparently it’s rush hour,” Kurt replied. “Let’s hope they’re not here on our account.”

As the vehicles pulled up in front of the bluff, the quiet desert filled with commotion. The headlights blazed and the dust swirled and voices rose through it, not arguing but discussing something tersely in Arabic. Armed men appeared from the mouth of a cave and walked out to greet the newcomers.

On the bluff above, the helicopter was shutting down. Two men climbed out and made their way toward the side of the cliff, disappearing into what looked like a hole cut out of the rock. Kurt guessed it was some kind of tunnel or hidden entrance.

“Come on,” he said, “while the valet’s busy with all those cars.”

Kurt backed down the sand dune for a few paces and began to scamper along it. Joe followed, trying to catch up.

“What are we going to do?” Joe asked. “Walk right in and pretend we’re with the band?”

“No,” Kurt said. “We make our way around the back by that landing pad. I saw the passengers from that chopper disappear without climbing down. Somewhere on top there must be a way in. All we have to do is find it.”

CHAPTER 19

OUT OVER THE INDIAN OCEAN, MARCHETTI HAD PUT THE airship into a slight climb, brought it up to an altitude of a hundred feet and slowed it considerably. To make the design as sleek as it was required some compromises, one of which meant the craft didn’t have quite enough buoyancy to float without some forward motion providing lift.

As the engine cut out and they started drifting, the passengers grew nervous.

“We’re still sinking,” Gamay said. Seventy feet below the sea was calm and dark. If she was right and that darkness was related to the microbots swarming beneath the surface, she had no desire to land on it.

“Just a second,” Marchetti said.

He threw a lever, and compartments at either end of the airship sprang open like he’d popped the trunk and hood of his car at the same moment. The hissing of high-pressure gas followed, and two additional balloons sprang forth from the hatches. They floated upward, quickly filling to capacity with helium and snapping their tether lines taut. As they inflated, the sinking slowed and then stopped.

“I call them air anchors,” Marchetti said proudly. “We’ll deflate them once we get moving again. But in the meantime, they keep us from ending up in the drink.”

Gamay was relieved to hear that. Around her, Leilani and Paul both exhaled.

“I guess we should break out the sampling kit,” Paul said.

The airship stabilized at forty feet. By releasing small amounts of helium, Marchetti coaxed it down to five feet and then set its buoyancy at neutral.

“Close enough?” he asked.

Paul nodded as he climbed toward the aft platform with the telescoping sample collector.

“Be careful,” Leilani said, looking as if she didn’t want to go anywhere near the edge.

“I second that,” Gamay added. “It’s taken me years to train you. I’d hate to start over with a new husband.”

Paul chuckled. “And chances are, you’d never find one as handsome and debonair as me.”

Gamay smiled. She’d never find one she loved as much as him, that was for sure.

As Paul reached the edge, Gamay moved up beside him. Knowing what lay below, she wanted to strap him in like a lookout at the top of the crow’s nest, but there was no way to do it, and no real need.

They were in the gyre of the Indian Ocean, near its center, a spot sort of like the eye of a hurricane. Under normal conditions it was “the doldrums,” with no wind or waves to speak of.

The sea below looked oily and flat, the sun blazed down from behind them. It was remarkably calm. Only the slightest of breezes could even be felt, not enough to worry about as they drifted a few feet above the water.

Paul extended the pole and dipped the vial in the water, scooping up a sample. He pulled the vial free and held it over the water, allowing the excess to drip off before reeling it in.

Wearing thick plastic gloves, Gamay took the sample and wiped the outside of the vial with a specially charged microfiber towel that Marchetti said would attract and trap any microbots that might be present.

She didn’t see any residue, but the little suckers were small. A hundred could fit on the head of a pin.

She glanced at the water in the vial.

“It looks clear,” she said.

She capped the vial and placed it in a stainless steel box with a rubber seal, which she wrenched down tight. She put the towel in a matching container.

Gamay and Paul gazed into the waters down below the way people might look over the edge of a dock. A few feet out the water looked normal. But they’d flown over two miles of discolored ocean since the dolphins scattered. It made no sense.

“They’re not on the surface,” Gamay said, realizing the truth. “We can see them, looking straight down, but at any kind of an angle all we can make out is seawater.”

From the cockpit Marchetti agreed. “They’re floating just below. You’ll have to get a deeper sample. If you want, I can take us right down to the—”