She shook Maria harder, shook her until her head was jerking back and forth.

"What are you doing?" Maria demanded.

"You talked!" Isabel stared at her. Maria's blue eyes had lost that creepy blank look.

"Of course I talked. You were practically shaking my head off," Maria answered.

"Are you okay?" Isabel demanded. "Should I go get someone?"

"I'm okay," she answered. "But what are we doing in here?"

Isabel felt her spine turn to ice. "Don't you remember?" she asked. "You totally spaced in English."

"Uh-uh." Maria shook her head. "I, um, I knew I shouldn't have eaten that candy bar Alex gave me. Sugar totally messes me up." She grabbed Isabel by the arm. "Come on, we better get back to class."

"Maria, what's going on?" Isabel pressed.

"Nothing. Nothing, I'm fine," Maria insisted. "Let's go."

Frowning, Isabel followed her out into the hall. Maria sounded completely fine. But there was no way a little sugar could have gotten that reaction.

No possible way.

Max sat on the floor of the cave and leaned against the cool limestone wall behind him. He felt like he'd pulled a muscle in his brain, a muscle he hadn't even realized was there. Ray had been trying to teach them how to do that time-freezing thing he'd done at the mall. But neither Max nor Michael had gotten close to getting it right.

"Using your brain is more tiring-and more difficult-than using your body," Ray said. He lowered himself onto a big rock across from Max. Michael didn't waste any time sitting. He stretched out flat on his back on the floor.

"Wait. Did you just read my mind again?" Max demanded. The stuff Ray could do was amazing. Thinking about it made Max's head hurt even more.

"Just a little," Ray answered.

He must have caught the look of panic and embarrassment on Max's face-or else read Max's mind again-because he laughed. "Don't worry, when I do it, I don't go too deep. I don't want to bump up against anything too personal. You never know what you're going to find in a teen's head."

Ray pulled a Lime Warp out of his backpack. He popped the top of the drink. "Want one?" he asked.

"That stuff tastes like goat piss," Michael complained. But he took a Lime Warp, anyway, then flopped back down next to Max.

"You know this for a fact?" Max asked. He grabbed a can from Ray. "You've actually tasted goat piss and can make an accurate comparison?"

"There are times you sound way too much like that science guy on TV," Michael said. "You know-the walking, talking dork?" He took a slug of his drink, then studied the can. "I still can't believe this is what we really look like. No offense, Ray."

Max glanced at the little dancing alien on the can. It did have the same small body, big head, and huge, almond-shaped, pupil-less eyes as everyone Ray had shown them on the spaceship.

"No, you've got it wrong. Well, sort of," Ray told Michael. "This form"-he pointed to the drawing on the Lime Warp can-"isn't any more our true appearance than this one." He gestured to his human body.

Max pressed his soda can against his pounding head. Ray had kept the drinks icy cold by slowing down the movement of the molecules. Max could have done that, too-if he'd thought of it-but it would have taken total concentration. Ray did it as easily as popping the top of the cans.

"I'm confused," Max admitted. "Maybe it's because I still have brain strain, but I don't get it."

"It's not all that complicated," Ray answered. "Here's the short version. Our bodies are highly adaptable. They adjust to whatever environment we're in. That means we can travel to any planet without the elaborate space suits humans use because our bodies automatically configure themselves for optimal functioning. Even on our own planet our bodies change, depending on factors like the climate."

"Can I just say, huh?" Michael asked.

"I sort of get it," Max said. "Earth is an environment with an oxygen-rich atmosphere. So our bodies configured themselves to breathe oxygen. Is that what you mean?"

"Ding, ding, ding. Give the boy a prize," Ray called out. "That's it exactly. What you just described is one of the thousands of ways our bodies adapt."

"Okay, I know I haven't read every science book in the world, like Max has, but I do know human bodies aren't the best choice for adapting to life in the desert," Michael said. "How come we don't look more like scorpions or cacti or something?"

"The answer is that our bodies don't just adapt to the physical environment," Ray said. "They adapt to the social environment, too. Humans are the species that dominates the planet, so our adaptation system gave us bodies to match theirs."

"So how do these guys fit in?" Max held up the Lime Warp can.

"Another adaptation, this time to life in space. The density of the small bodies protects their internal systems from the effects of rapid space travel. And the small bodies take up less space on board, freeing up room for more important items," Ray said.

"Cool," Michael said.

"Very cool," Max agreed. "Could you show us some hologram pictures, or whatever you call them, of some of the adaptations we have at home?"

"Home. I don't understand why you're calling it home," Ray said. "This is your home. Earth. It was a mistake for me to tell you anything about… that other place. I try to think of it as a dream, a beautiful dream. But not something real, not something I can ever go back to. This is my home now, too."

He sounded so sad suddenly, not his usual joking self. Max wondered how he would feel if he had to make a life on another planet, knowing he'd never see his parents or Liz or anyone else he cared about again. He didn't know if he'd cope as well as Ray seemed to have.

Ray stood up. "Let's get out of here."

"So that's it. You're not answering any more questions? You're just deciding for us that we shouldn't know anything about where we come from?" Michael demanded.

Ray looked directly at Michael. "I'm not going to encourage you to spend your lives wishing you were someplace else," he said. "Your lives are here. Get on with them."

"Thanks for nothing," Michael muttered.

Ray turned to Max. "I know it must seem that I'm being incredibly harsh. But trust me, living one place when your heart and mind are always somewhere else is guaranteed to make you miserable."

Max didn't want to push Ray. It was pretty clear that he was protecting himself as much as he was Max and Michael. But there was one thing he had to know.

"Can you just tell-" Max said.

"Max, I've made up my mind," Ray interrupted.

"This is important," Max insisted. "I just want to know if there's anything you can teach me that will help protect us from Valenti."

Ray sighed. "I guess that is something you actually do need to know. We can do some more work freezing time inside a particular location. But that's not something you can do often. I won't be able to do it again myself for at least a month-it takes too much energy."

"Is there anything else?" Max asked. He wanted to be prepared, no, he needed to be prepared if he had to go up against Valenti again. It's not like Ray would always be able to come to the rescue.

"Lay low. That's what got me through the last fifty-something years," Ray answered.

"That's it? Lay low?" Michael demanded.

"Well, there is a little trick I use sometimes," Ray admitted. "Watch this."

"Watch what?" Max asked. Then he saw it. Ray's face was moving. His hair was growing and darkening. His body was shrinking and changing shape.

He looked like… Liz. Ray looked like Liz.

"Aaaah." Michael gave a high, comical shriek.

"We can also give ourselves little makeovers whenever we want to change our appearance," Ray said. He even sounded like Liz. "I gave myself one after the crash. I didn't feel like being the scientist the people in Roswell knew anymore."