Piper charged her, but before a fight could start, Coach Hedge barked, “Enough back there! Set a good example or I’ll break out my baseball bat!”

The group shuffled on to the next exhibit, but the girls kept calling out little comments to Piper.

“Good to be back on the rez?” one asked in a sweet voice.

“Dad’s probably too drunk to work,” another said with fake sympathy. “That’s why she turned klepto.”

Piper ignored them, but Jason was ready to punch them himself. He might not remember Piper, or even who he was, but he knew he hated mean kids.

Leo caught his arm. “Be cool. Piper doesn’t like us fighting her battles. Besides, if those girls found out the truth about her dad, they’d be all bowing down to her and screaming, ‘We’re not worthy!’”

“Why? What about her dad?”

Leo laughed in disbelief. “You’re not kidding? You really don’t remember that your girlfriend’s dad—”

“Look, I wish I did, but I don’t even remember her, much less her dad.”

Leo whistled. “Whatever. We have to talk when we get back to the dorm.”

They reached the far end of the exhibit hall, where some big glass doors led out to a terrace.

“All right, cupcakes,” Coach Hedge announced. “You are about to see the Grand Canyon. Try not to break it. The skywalk can hold the weight of seventy jumbo jets, so you featherweights should be safe out there. If possible, try to avoid pushing each other over the edge, as that would cause me extra paperwork.”

The coach opened the doors, and they all stepped outside. The Grand Canyon spread before them, live and in person. Extending over the edge was a horseshoe-shaped walkway made of glass, so you could see right through it.

“Man,” Leo said. “That’s pretty wicked.”

Jason had to agree. Despite his amnesia and his feeling that he didn’t belong there, he couldn’t help being impressed.

The canyon was bigger and wider than you could appreciate from a picture. They were up so high that birds circled below their feet. Five hundred feet down, a river snaked along the canyon floor. Banks of storm clouds had moved overhead while they’d been inside, casting shadows like angry faces across the cliffs. As far as Jason could see in any direction, red and gray ravines cut through the desert like some crazy god had taken a knife to it.

Jason got a piercing pain behind his eyes. Crazy gods ... Where had he come up with that idea? He felt like he’d gotten close to something important—something he should know about. He also got the unmistakable feeling he was in danger.

“You all right?” Leo asked. “You’re not going to throw up over the side, are you? ’Cause I should’ve brought my camera.”

Jason grabbed the railing. He was shivering and sweaty, but it had nothing to do with heights. He blinked, and the pain behind his eyes subsided.

“I’m fine,” he managed. “Just a headache.”

Thunder rumbled overhead. A cold wind almost knocked him sideways.

“This can’t be safe.” Leo squinted at the clouds. “Storm’s right over us, but it’s clear all the way around. Weird, huh?”

Jason looked up and saw Leo was right. A dark circle of clouds had parked itself over the skywalk, but the rest of the sky in every direction was perfectly clear. Jason had a bad feeling about that.

“All right, cupcakes!” Coach Hedge yelled. He frowned at the storm like it bothered him too. “We may have to cut this short, so get to work! Remember, complete sentences!”

The storm rumbled, and Jason’s head began to hurt again. Not knowing why he did it, he reached into his jeans pocket and brought out a coin—a circle of gold the size of a half-dollar, but thicker and more uneven. Stamped on one side was a picture of a battle-ax. On the other was some guy’s face wreathed in laurels. The inscription said something like ivlivs.

“Dang, is that gold?” Leo asked. “You been holding out on me!”

Jason put the coin away, wondering how he’d come to have it, and why he had the feeling he was going to need it soon.

“It’s nothing,” he said. “Just a coin.”

Leo shrugged. Maybe his mind had to keep moving as much as his hands. “Come on,” he said. “Dare you to spit over the edge.”

They didn’t try very hard on the worksheet. For one thing, Jason was too distracted by the storm and his own mixed-up feelings. For another thing, he didn’t have any idea how to “name three sedimentary strata you observe” or “describe two examples of erosion.”

Leo was no help. He was too busy building a helicopter out of pipe cleaners.

“Check it out.” He launched the copter. Jason figured it would plummet, but the pipe-cleaner blades actually spun. The little copter made it halfway across the canyon before it lost momentum and spiraled into the void.

“How’d you do that?” Jason asked.

Leo shrugged. “Would’ve been cooler if I had some rubber bands.”

“Seriously,” Jason said, “are we friends?”

“Last I checked.”

“You sure? What was the first day we met? What did we talk about?”

“It was …” Leo frowned. “I don’t recall exactly. I’m ADHD, man. You can’t expect me to remember details.”

“But I don’t remember you at all. I don’t remember anyone here. What if—”

“You’re right and everyone else is wrong?” Leo asked. “You think you just appeared here this morning, and we’ve all got fake memories of you?”

A little voice in Jason’s head said, That’s exactly what I think.

But it sounded crazy. Everybody here took him for granted. Everyone acted like he was a normal part of the class—except for Coach Hedge.

“Take the worksheet.” Jason handed Leo the paper. “I’ll be right back.”

Before Leo could protest, Jason headed across the skywalk.

Their school group had the place to themselves. Maybe it was too early in the day for tourists, or maybe the weird weather had scared them off. The Wilderness School kids had spread out in pairs across the skywalk. Most were joking around or talking. Some of the guys were dropping pennies over the side. About fifty feet away, Piper was trying to fill out her worksheet, but her stupid partner Dylan was hitting on her, putting his hand on her shoulder and giving her that blinding white smile. She kept pushing him away, and when she saw Jason she gave him a look like, Throttle this guy for me.

Jason motioned for her to hang on. He walked up to Coach Hedge, who was leaning on his baseball bat, studying the storm clouds.

“Did you do this?” the coach asked him.

Jason took a step back. “Do what?” It sounded like the coach had just asked if he’d made the thunderstorm.

Coach Hedge glared at him, his beady little eyes glinting under the brim of his cap. “Don’t play games with me, kid. What are you doing here, and why are you messing up my job?”

“You mean...you don’t know me?” Jason said. “I’m not one of your students?”

Hedge snorted. “Never seen you before today.”

Jason was so relieved he almost wanted to cry. At least he wasn’t going insane. He was in the wrong place. “Look, sir, I don’t know how I got here. I just woke up on the school bus. All I know is I’m not supposed to be here.”

“Got that right.” Hedge’s gruff voice dropped to a murmur, like he was sharing a secret. “You got a powerful way with the Mist, kid, if you can make all these people think they know you; but you can’t fool me. I’ve been smelling monster for days now. I knew we had an infiltrator, but you don’t smell like a monster. You smell like a half-blood. So—who are you, and where’d you come from?”

Most of what the coach said didn’t make sense, but Jason decided to answer honestly. “I don’t know who I am. I don’t have any memories. You’ve got to help me.”

Coach Hedge studied his face like was trying to read Jason’s thoughts.

“Great,” Hedge muttered. “You’re being truthful.”

“Of course I am! And what was all that about monsters and half-bloods? Are those code words or something?”

Hedge narrowed his eyes. Part of Jason wondered if the guy was just nuts. But the other part knew better.

“Look, kid,” Hedge said, “I don’t know who you are. I just know what you are, and it means trouble. Now I got to protect three of you rather than two. Are you the special package? Is that it?”

“What are you talking about?”

Hedge looked at the storm. The clouds were getting thicker and darker, hovering right over the skywalk.

“This morning,” Hedge said, “I got a message from camp. They said an extraction team is on the way. They’re coming to pick up a special package, but they wouldn’t give me details. I thought to myself, Fine. The two I’m watching are pretty powerful, older than most. I know they’re being stalked. I can smell a monster in the group. I figure that’s why the camp is suddenly frantic to pick them up. But then you pop up out of nowhere. So, are you the special package?”

The pain behind Jason’s eyes got worse than ever. Half-bloods. Camp. Monsters. He still didn’t know what Hedge was talking about, but the words gave him a massive brain freeze—like his mind was trying to access information that should’ve been there but wasn’t.

He stumbled, and Coach Hedge caught him. For a short guy, the coach had hands like steel. “Whoa, there, cupcake. You say you got no memories, huh? Fine. I’ll just have to watch you, too, until the team gets here. We’ll let the director figure things out.”

“What director?” Jason said. “What camp?”

“Just sit tight. Reinforcements should be here soon. Hopefully nothing happens before—”

Lightning crackled overhead. The wind picked up with a vengeance. Worksheets flew into the Grand Canyon, and the entire bridge shuddered. Kids screamed, stumbling and grabbing the rails.

“I had to say something,” Hedge grumbled. He bellowed into his megaphone: “Everyone inside! The cow says moo! Off the skywalk!”

“I thought you said this thing was stable!” Jason shouted over the wind.

“Under normal circumstances,” Hedge agreed, “which these aren’t. Come on!”

THE STORM CHURNED INTO A MINIATURE HURRICANE. Funnel clouds snaked toward the skywalk like the tendrils of a monster jellyfish.

Kids screamed and ran for the building. The wind snatched away their notebooks, jackets, hats, and backpacks. Jason skidded across the slick floor.

Leo lost his balance and almost toppled over the railing, but Jason grabbed his jacket and pulled him back.

“Thanks, man!” Leo yelled.

“Go, go, go!” said Coach Hedge.

Piper and Dylan were holding the doors open, herding the other kids inside. Piper’s snowboarding jacket was flapping wildly, her dark hair all in her face. Jason thought she must’ve been freezing, but she looked calm and confident—telling the others it would be okay, encouraging them to keep moving.