"Good; let's keep it that way. Dr. Byrne needs to have a miraculous recovery. I'm pretty sure that's the only way I can get you out of here."

"A recovery?"

"Pretend it's all coming back to you. From what I understand you were conducting an experiment, using laser-generated micro black holes."

Her mom laughed drily. "That's ironic. That's almost exactly what I was doing when I ended up here."

"Really?"

"Controlled creation of micro black holes using ultradense deuterium and laser-generated fusion." Her mom shook her head. "Apparently not so controlled. We had a small explosion in the lab. I blacked out for a moment, and woke up here. In this world."

"That would explain it. If you and the other Dr. Byrne were doing the same experiment at the same time." Josie made an explosion motion with her hands. "Boom."

Her mom nodded. "Any idea what composition of deuterium they were using?"

"No, only that it was an injectable compound."

"An injectable? That's amazing. I'd love to see the formula."

"Do you think it would help?" Josie asked. "If you knew what was in the formula, maybe how it caused the explosion that sent you here, do you think we could figure out a way to get home?"

Her mom thought for a moment. "Maybe. Do you have the injectable?"

Josie bit her lip and gave an almost imperceptible nod of her head. Then she cleared her throat. "No. No, I don't," she said loudly, in case anyone was listening.

There was a commotion outside the cell and Josie heard hurried footsteps clicking across the floor. They didn't have much time.

"We're trying to figure a way to get you out of here," Josie said quickly.

Her mom's face went blank. "We?"

"Some friends of mine."

Josie's mom gripped her arm tightly, digging her fingers into Josie's flesh. "Don't trust them. You can't. Josie, you can't trust anyone here, do you understand me?"

Dr. Cho rushed into the room. "I'm sorry," she said breathlessly. "I'm afraid your mother is due for her medication now. We'll need to cut your visit short."

Josie forced the sunny smile back onto her face. "Oh, that sucks."

"Hospital regulations," Dr. Cho replied.

More like prison regulations.

Josie stood up, but her mom pulled her back, wrapping her arms tightly around her neck.

"You can't trust anyone," she whispered frantically.

A cold sensation spread down Josie's spine, like an ice cube melting against her skin. All of her hope in getting her and her mom home rested in the trust she'd put in people: Nick, Penelope, even Mr. Byrne in his ignorant way. Had she been wrong? Was she placing them in even worse danger?

"I love you too, Mom," she said out loud, pulling away. The image of her mom's haunted, bloodshot eyes followed her from the room.

3:59 P.M.

Jo tiptoes down the hallway, careful to avoid the creaking floorboard right outside her mom's room. She can't wake up. Her mom would have a fit if she knew what Jo is about to do.

She opens the door to the basement a centimeter at a time. Her heart pounds in her chest. She has to hurry. It's already time.

Jo flips on the desk lamp in her mom's makeshift lab and squints against the light. The darkness is so lovely, but she needs to see what she's about to do.

The mirror faces the wall with a heavy wood beam leaning against it, securing it to the concrete. Jo crouches under it, pushing up with her legs and lifting the beam with her shoulder. She pivots a few inches, then lets the beam come to rest against the wall itself, freeing the mirror, if only temporarily.

Jo pulls the letter from her pocket as she eases the mirror away from the wall. The mirror's surface is smooth, reflecting Jo's old bedroom. But Jo doesn't waste any time. She reaches through the portal and drops the letter on the floor of her room, then lowers the mirror. . . .

"Wait!" Josie screamed.

The car swerved. "Whoa," Nick said, both hands firmly gripping the wheel. "What the hell?"

She'd fallen asleep in the car. "Jo," she said breathlessly.

Nick's head snapped in her direction. "Did you have another dream?"

"She opened the portal."

"What?"

"She put a note through." Josie pounded on the dashboard. "Fuck! Why wasn't I there?"

It was too much. The portal, her mom. Too much. Josie hung her head in her hands and cried.

FORTY-ONE.

4:21 P.M.

"HEY," NICK SAID SOFTLY. HIS HAND CARESSED her shoulder. "It's okay. It's going to be okay."

Josie wasn't sure how long she'd been crying, but apparently Nick had pulled the car off to the side of the road and killed the engine. She looked at him, his face sad and calm, and tried to control herself. After a few moments, her sobs, though still erratic, were less frequent, but she felt weak and helpless.

"If only I'd been there," she said, wiping tears from her cheek. "I could have-"

"You could have what? Beaten the crap out of Jo?"

Josie smiled. "Maybe." The thought was appealing.

"But it wouldn't have done your mom any good. She'd still be in that hospital, and it's not like you could force Dr. Byrne to go back and clear everything up."

The boy had a point.

"You said it yourself: your best chance is to replicate the experiment that landed your mom here in the first place."

Josie nodded. He was right. She knew he was right.

"And I'm going to help." His eyes swept over to her face, down to her neck, and fixed on something there. The necklace. He shook his head, as if snapping himself out of a dream, and quickly sat up straight. He started the car and pulled back onto the highway. "Let's see what Jo had to say, huh? Now I'm curious."

4:40 P.M.

Josie, I'm sorry about all this.

There's more going on than you know. Even if I could tell you, I doubt you'd believe me. I'm sure you hate me right now, but believe me when I say I didn't have a choice.

But maybe I can make it up to you.

I need to find something. I thought it was here, but I don't know if you noticed all the strange items that were switching back and forth between our worlds for the last couple of weeks? I had been missing a pair of shoes that miraculously reappeared a few days after I'd torn the house apart looking for them. Things like that. Back and forth without any warning.

The thing I'm looking for? That's what happened to it. I think.

You need to search the house when Teresa and Daddy are gone for a black kitchen canister filled with coffee. Yes, I realize that sounds totally bizarre, but I need that canister.

In twenty-four hours I'll reopen the portal and then, if you have the canister, we can both go home. Deal?

-Jo Nick lowered the note to the bed and shook his head. "Yep," he said. "This totally sounds like Jo."

"Does it?"

"The tone. The way she tries to make you feel that she's sharing with you when really she's playing everything close to the vest. Just like her mom."

Josie was intrigued. "Yeah?"

"My brother said she was single-minded about her job. Like a sociopath, practically."

"I noticed," Josie said with a dry laugh.

"Which made her a good scientist, but a crappy colleague."

"I can see that." Dr. Byrne was utterly and completely obsessed with her work. "Do you think she did it? Do you think she's the one who sabotaged the experiment and was going to sell your brother's formula to the highest bidder?"

"I wouldn't be surprised," Nick said. "I mean, she was cold-blooded enough, clearly hiding something. And you did find the chat transcript in her office. If she was suspicious that someone else was the traitor, wouldn't she have gone to the authorities? She definitely would not have continued the experiment if she thought it was sabotaged, you know?"

Josie shuddered, thinking about the woman she'd been living with for the past six months. A woman who apparently had no compunction about letting people die in exchange for a hefty payday.

"Jo's like that too," Nick continued. "Single-minded. When she decides on something she wants, she doesn't stop till she gets it."

Josie smiled. "Like you?"

He steadily met her gaze. "And you."

"Wish I'd known that four days ago."

Nick leaned toward her. "Wish I'd known you four days ago."

Josie wasn't exactly sure what that meant, but it made her feel all warm and fluttery inside. She picked up the letter and lay back on her bed, propping her head up with a pillow as she read through it again. The note was so calculated. Josie could see that now-the cool, collected machinations of the Jo that everyone here seemed to know and loathe.

Why hadn't she seen it before? Hard to say. Josie had seen what she wanted to see: a perfect family and a boyfriend who adored her.

But now, Josie had the upper hand. It was what Jo omitted from her note that was the most interesting. No mention of Josie's mom at Old St. Mary's. No explanation as to why she'd tricked Josie into switching places. She didn't want Josie to know that she'd reunited with her mom.

Because Jo and her mom had no intention of switching back.

"What are you thinking?" Nick asked softly, lying down next to her.

"They don't want to come back," she said. "Jo and her mom. I've seen it in my dreams. Dr. Byrne is terrified. She's lost the vial of the injectable formula, which was her only bargaining chip. She knows she'll be blamed for sabotaging the experiment and for your brother's death. And I think she's more scared of the Grid than anything."

"She should be." Nick inched his body toward her. "And what about Jo? Why doesn't she want to come back?"

"Jo's got her sights set on . . ." Josie stopped. She almost said, ". . . on my ex-boyfriend." But she hadn't told this Nick about his doppelganger in her world, and her relationship with him. Nick gazed at her as he lay on his side next to her, his face so close to her own she could feel his breath against her cheek. She couldn't tell him. Not now.

"Got her sights set on what?"

"Nothing." Josie quickly changed the subject. "What I don't understand is why."

Nick tilted his head. "What do you mean?"

She propped herself up on one arm. "I mean, why risk opening the portal? Why risk the exchange? For an injectable they have no use for? It doesn't make sense."

Nick pushed himself up on one elbow so his face was even with hers once more. "You're right. If there aren't Nox in your world, the antidote is useless."

"Right," Josie said. "And there aren't any . . ."

Her voice trailed off. She remembered something, a glimpse of a wing outside her kitchen window, something moving in the darkness, and a far-off scream that sounded like metal grating against a chalkboard. She'd passed it off as an eagle or an owl at the time, but now after what she'd seen of the Nox, the horrible realization dawned on her.

"Oh no," Josie said, flopping back onto her pillow. "I'm such an idiot."

"Hardly," Nick said with a short laugh. "You're like the smartest person I've ever met."

Normally the compliment would have made Josie all goo-goo, but the mysterious deaths that had plagued her hometown suddenly all made sense. She'd been so stupid not to see it before.

"Dr. Byrne wants the vial," she said, her mouth suddenly dry, "because there are Nox in my universe."

"Wait," Nick said. "I thought you said there weren't any?"

"There weren't," she said. "Were not. As in past tense." She gave Nick a rough sketch of the dead bodies that had been turning up in the woods outside of town. Victims of animal attacks, partially eaten, always killed at night.