“It’s so green,” said Ren as the ferry bumped slowly into its moorings.

Alex looked around. The western bank was lined with fat-trunked trees and dense bushes, all soaking up the water that had given birth to Egyptian civilization five thousand years earlier, and sustained it ever since.

As they filed off the boat, a few returning passengers filed on. Two of them moved gingerly, as if very old or injured. As they shuffled by, Alex couldn’t help but suck a sharp breath in through his teeth.

Their faces and arms were horribly burned. And judging by their stiff, pained movements, that wasn’t all.

“Don’t stare,” a voice whispered.

Alex turned and saw a tall woman with dark brown hair pulled back in a no-nonsense ponytail. His heart nearly stopped. But then he met her gaze, and instead of his mom’s steely blue-gray eyes, he saw a soft shade of hazel looking back at him. She looked away, turning to face one of the boat’s crew.

“Shukran,” she said, taking a tightly wrapped paper bundle from him and discretely slipping him a few folded bills.

“Al’awf,” he said, nodding slightly.

“I wasn’t staring,” said Alex, when she turned back to him.

“You were,” she said, not harshly, but firmly enough to settle the matter. She was wearing threadbare khaki pants and a short-sleeved, button-up shirt that may once have been white. On her head was a faded red baseball cap with the white H of Harvard on the front. On her feet, the same sort of battered leather boots his mom had always packed for trips to the desert.

Ren eyed the cap. She was the type of twelve-year-old who already had a first-choice college picked out, and Alex knew that was it. “I’m Ren,” she said.

“I’m …” the lady began before pausing a beat. Alex had seen his mom do that, too, deciding whether to introduce herself as Dr. Bauer or Maggie. He knew immediately this lady was an academic. “Isadore,” she continued, “but you can call me Izzie. All of the other crazies out here do.”

“How do you know we’re crazy?” said Alex, not bothering to deny it.

Izzie’s only answer was another small smile and a quick look behind them for any signs of parents.

“What happened to those people?” asked Ren. “Were they in a fire?”

“Sunburn,” said Izzie. A strange expression flashed across her face. “They say it happened last night,” she said softly.

“That’s impossible,” said Alex, remembering the open blisters on their faces, the wet stains oozing out from under the fresh gauze on their arms.

But Izzie was already stepping briskly off the dock, and her only response was an over-the-back wave good-bye.

They waded out into the parking lot, a fresh blast of heat hitting them as soon as they stepped on the sun-softened blacktop. Alex had no idea how two people could get such brutal sunburns at night, but he could easily see how it would happen during the day out here. He glanced at Luke’s Yankees cap and wished he’d thought to pack his Mets cap — sickly for most of his life, he’d always identified with underdogs.

Alex looked around. They were at the gateway to what had long been one of the world’s top tourist destinations. But they seemed to be the only tourists there today, and a handful of eager taxi drivers were beginning to circle. Rising up in the distance behind them was the first phalanx of hotels.

“A real hotel would be nice,” said Ren a little wistfully. “No rats …”

“We can’t get a hotel,” said Alex, lowering his voice as the first of the drivers approached. “Three kids with U.S. passports … How long do you think it would take The Order to find out about that?” Left unsaid: There’s no way my mom will be there, either.

Alex waved off the first few taxi drivers and headed for the edge of the parking lot. The other two followed.

“Well, where, then?” said Ren.

“Yeah,” said Luke. “What’s your big idea?”

Alex had decided after nearly getting nabbed in the little shoe-box sleeper car: No more tight spaces. He pointed up at the low-slung building in front of them. The sign above it was crowded with a few dozen words in Arabic, but only two in English: CAMPING SUPPLIES!

“We go no farther,” the taxi driver said firmly. He pulled over to the side of the road, the desert stretching out around them.

“We’re not even in the Valley of the Kings yet,” Alex said, scanning some of the signs next to the road.

“Exactly,” said the driver. “It is too hot in the valley now.”

It was one o’clock on the nose, and the sun was almost directly overhead. But Alex wasn’t sure that’s what the driver meant by “now.” Those burned arms and the bandages …

“Has something happened in the Valley of the Kings?” said Alex. “Has something changed?”

“Everything has changed,” the driver said bitterly. “I leave you here, along with the other …” He paused to find the right phrase and then spat it at them. “Thrill seekers.”

They were dumped out into the sizzling heat along with all their stuff: their small backpacks stuffed inside big, new ones. It definitely wasn’t much of a thrill. Alex glanced up into the cloudless sky and was blinded by the blazing sun.

“Where now?” said Ren.

This time Alex had no answer. “Do I look like the kind of kid who’s been on campouts before?”

“I have,” said Luke. “Hiking’s awesome for the legs. Throw in some rock climbing, and it’s a killer total body workout.”

“I’m not looking for a killer workout,” said Ren. “Just, you know, not getting killed.”

“Nice one, short-stuff,” said Luke, pointing at her with both index fingers. “Point is: The first thing you need to do is find shelter. Like from the wind —”

“Or the heat,” said Alex, pulling his new hat out of his backpack. It was round and flat on top, with a bill in the front and a curtain of cloth in the back that covered his ears and neck.

Luke and Ren glanced at each other and laughed softly. Alex pretended not to notice as he put it on.

The landscape was mountainous at the edge of the valley. Long ridges scraped the sky in both directions, jagged, rocky fins erupting upward from the sunbaked ground. When Alex thought of desert, he thought of softly drifting sand, but the rim of the valley was stony and hard. He kicked the toe of his new boot into the ground and got a solid thud in return. He could feel the heat radiating up from it right through the leather. A sense of dread descended on him. This is an unforgiving landscape, he thought.

He turned and looked toward Ren. Luke did, too.

“What are you guys looking at me for?” she said.

But they weren’t looking at her; they were looking at her amulet.

“Ask it where the best shelter is,” said Alex.

Ren’s reluctance was obvious: She refused to even look down at the ibis.

“Come on,” said Luke. “It’s hot out here.”

He had settled into a role that was less decision-maker than tie-breaker, joining Ren in laughing at Alex one minute and siding with Alex against her the next. Now she was outvoted. She frowned and then … “Wait!” she said. “It’s telling me something.”

“Really?” said Luke, gaping at the amulet.

“You aren’t even holding it,” said Alex, incredulous. Did she no longer need to do that? Had Ren somehow leapfrogged him in amulet use?

“Yeeessss,” said Ren, her voice sounding ghostly and far away.

They both watched, rapt, as she quickly knelt down.

“The power of the ancient amulet is telling me …”

Her hands moved quickly, and a moment later she stood back up.

“To use my eyes.”

She was holding the new binoculars they’d just purchased at 40 percent off.

“There’s some shadow up there, along the top of the ridge,” she said. “Looks like good shelter. And wait … Yeah … There are some people camping up there already.”

“I guess those are the ‘thrill seekers,’ ” said Alex. “Is there space for us up there? I mean, without getting too close?”

“Plenty,” said Ren.

“Let’s go there,” said Luke, hoisting his pack onto his back. “We can at least follow people who know what they’re doing.”