Dr. Brooke took Elena and Patrick back to the staff lounge. There was no one else in there. Sam's arrival had apparently given everyone a new task to occupy themselves.

Again, Patrick wouldn't look toward her, but this time she didn't blame him. She pulled out her phone, and in the moment before the screen lit up, she could hardly stand to see her own face reflected on the shiny surface. He had been right. Of course, he had been right.

She stared for a long time at the menu page on her phone. Michelle had told her she needed to solve this mystery, had believed she could. Elena had disagreed. Maybe she still disagreed. But if she was going to fulfill what she had said to Patrick, about not having been a coward, she couldn't become one now. She had to keep trying.

Because she wasn't going to let Sam die alone. If it came down to it, she'd go in there and be with him in his last moments. Even if it was torture. Even if it killed her. It was no less than she deserved.

A little voice in her head whispered that it had already come down to that. She had already failed.

If only she could have someone to bounce ideas off of. She'd loved to have been able to talk to Patrick, but he still wasn't even looking toward her. Besides, he wouldn't understand a word she said.

Her dad would have understood. She swallowed against the tightness in her throat.

She scrolled through her contacts. Her finger hovered over Michelle's number. Elena would have to confess what she had done, how wrong she had been. Patrick's disapproval stung; Michelle's might as well be evisceration. But she would find out what had happened sooner or later, assuming she was alive.

Assuming she was alive.

She finally hit the call button. It rang for eternity before Michelle's voicemail played.

Her contacts list reappeared. Right below Michelle's name was another she had barely talked to, despite Michelle's promptings: Mom.

This could be her last chance. She hit the call button.

Her mom picked up on the third ring. "Are you okay, Elena?"

Elena's eyes stung. "Mom." Her voice broke.

"What's wrong?"

"I'm stuck, Mom. I got myself in a bad situation, and if I can't get myself out of it . . ." A single hot tear rolled down her cheek. "I'm not going to make it."

"Where are you, Elena? I'm going to come get you. I'm coming right now."

"I don't think you can help me."

"I don't care. I'm coming to help you."

"It's—it's not that kind of thing. You can't solve this one."

"You're the last family I have, Elena, now tell me where you are!"

"You can't help me, Mom, not with this one!"

"Then why did you call me?"

"Just . . . to say I'm sorry. Sorry for blaming you for what happened to Dad. I know you were doing your best. And sorry I couldn't solve this problem I'm in right now. Sorry for leaving you."

"Elena, you listen to me." It was the voice Elena didn't dare ignore. "You're your father's daughter all the way through. You're brilliant, you can learn anything, solve anything, fix anything. But it gets tough and you give up and walk away, no matter what the consequences."

"It's not like that, Mom, it's—"

"No, I'm not done. I was never good with all those technical things you and your father loved, but I don't give up. I don't ever give up. Just this one, Elena, don't just be your father's daughter. Be mine, too."

She sniffled and wiped away her tears. "Okay, Mom."

"You come visit me when camp ends, okay? Don't just run off to the dorm. Come see me."

"Okay, Mom."

"Call me when you figure it out, okay?"

"Okay."

"Alright then."

Elena's hand shook as she lowered the phone. She glanced over at Patrick, who was still looking away from her, then lowered her phone to the table.

She could do this.

"I know you don't want to talk to me," she said.

He didn't respond.

She sighed. "I haven't given up trying to solve this thing. I think I can do it before they do anything crazy. But I can't do this alone."

He shifted just slightly, away from her.

"Look. I know you don't know much about science, but I don't know if that's the kind of help I need anyway. It's just . . . I've just got to be able to talk to someone. And Michelle's not picking up her phone."

Patrick still wasn't looking at her, but she could tell he was listening.

"So I'm just going to start talking." She took a deep breath. "Planck's constant isn't just for light and energy. It comes up in other places too. It came up a lot in the quantum class I had to take last semester. It's in the Schrodinger equation."

She couldn't explain quantum wave functions to Patrick, but she could break down the basics. "Quantum mechanics is weird. Like light. You know that a particle can be in more than one place at once? I mean, kind of. It's a probability thing. It's more like, a particle doesn't have a determined place."

He remained very still, as if waiting for her to go on.

"Okay, it's called the uncertainty principle. It's the idea that the more you know about where something is, the less you know about how fast it's going—or, like, how much energy it has, basically. But as soon as you measure exactly how fast it's going, you lose it, and now you don't know where it is anymore."

If Sam could lower Planck's constant, he could make it possible to measure particle locations and speeds more precisely, but she couldn't see the immediate applications of that. This wasn't time to be getting caught up in the magic of science, anyway. And Patrick didn't care.

"Sorry. Focusing again. You'd said earlier that it seemed like a crazy coincidence that Sam's powers just happened to be dormant his whole life and then come out of hiding when we met him. I mean, that's not how coincidence works, of course—we would never have noticed him if his powers hadn't come out at that moment, anyone could have been the first to notice them, we were just the ones who were there, nothing surprising or special about that—but that's not what you meant."

Patrick's nostrils flared.

Elena sighed. "The point is, you thought something needed to cause them to be dormant, or to come out of hiding. The more I think about it, the more I agree. I should have listened to you."

His expression softened, ever so slightly.

"Because if you think about it, they haven't been dormant his whole life. His parents knew what the anomalies were going to be, or they wouldn't have named him Planck. I mean, that would be one crazy coincidence, right? But it's not just that."

His eyebrows raised.

Even those subtle reactions were enough to help her thoughts flow more freely. "Sam's last foster home must have seen them taking effect, right? They even did some investigation into them. The anomalies must have gotten pretty bad, because his foster mom thought he'd been possessed by a demon."

She blinked a couple of times. "I guess we can't rule out demons, can we? We can't rule out anything. He could be an angel, or a demon, or an alien from an alternate universe. He could have been bitten by a radioactive mosquito. But it doesn't matter."

Patrick's brow furrowed.

"I mean, it matters to him, it matters on a much deeper level. It's where he came from. And it would be helpful information. But we don't have any good way of answering those questions right now, and if there is a way to stop the anomalies, it won't care what we know about where those anomalies came from."

She looked down at her hands and chuckled to herself. "Unless they're quantum. Like the uncertainty principle, right? The more you know about what it is, the less you can control—"

His eyes met hers.

She gasped. "I mean . . . no, there's no way."

"Low level powers his whole life, but every time someone tries to run experiments, they get worse. And if the people keep investigating, he just keep getting worse and worse—what did you say, exponentially?"

She bit her lip. "You think the anomalies are quantum."

"It fits."

It did, as far as she had seen, but they could come up with any number of crazy theories that fit. If they were on to something, though . . . She shook her head. "We'd notice. If we suddenly learned a huge new thing about the anomalies, they'd have suddenly grown increasingly erratic, the flux would have spiked, we'd probably hear—"

Alarms blared, and red lights flashed. The hallway outside the door came alive with running and shouting.

So it wasn't a coincidence: during that last conversation with Jim, every time she'd taken another step toward understanding, she'd felt like her headache was intensifying. It had felt that way because it really was.

Elena and Patrick exchanged a glance, then she jumped up to follow.