3:59

He had no idea.

3:59 A.M.

Her mom sits at the kitchen table. She rests her elbows on the laminate wood surface and holds a steaming cup of tea to her lips.

She closes her eyes and inhales deeply, relishing the aroma. “I dearly love a cup of tea,” she says on a breathy exhale.

“I know.”

“That woman only drank coffee. Bins of the stuff in the house, and not even a box of tea when I got here.” She stares lovingly at the box of tea bags on the table.

“Oh.”

“I can’t tell you how many mugs of that slime I’ve had to choke down at the lab.” She takes a long sip, then abruptly lowers the cup. “Speaking of, you’d better start making a list of what your other half did and didn’t do. We can’t have any suspicions if we’re going to stay here.”

“Stay here?”

Her mom arches an eyebrow. “Don’t you want to? You don’t really want to go back to all that, do you? The secrets and the lies. And the Nox.”

She shudders at the mention of the Nox, then shakes her head hesitantly. “No.” She pauses. “I don’t know. Maybe?”

“Don’t worry about your boyfriend,” her mom says sharply. “He’ll be fine.”

Jo’s stomach tightens up. “He’s not my boyfriend.” Not yet, she thinks to herself.

“We can’t go back,” her mom says with a nod of her head. “The mirror has to stay where it is. Besides”—her mom reaches across and pats her hand—“now that you’re here, I don’t have to worry about creating a new portal. That’s all I’ve been working on the last six months, you know. A way to bring you here.”

“Oh.” Jo tries to hide her anxiety. She doesn’t want to stay, not any longer than they have to. “Are you going to destroy the mirror?”

“I can’t,” her mom says. “Too dangerous. I have to find a way to close the portal first.”

“Oh.”

Her mom whisks away her hand. “It’s not so bad here, Josephine. I promise.”

Jo shivers. Her body feels suddenly cold.

“Get to know the other Nick,” her mom says. It’s like she can read her daughter’s mind. “Maybe you’ll like him.”

“I suppose.”

“Try,” her mom says. “Because once I figure out how . . .” She pauses and stares Jo directly in the eye. “We’ll destroy the portal. Forever.”

Josie’s eyes flew open and she pushed the sleep mask up over her head. They were still connected. She and Jo.

A hundred ideas flooded into her head at once. Her mom. The portal. Her mom.

Holy shit.

It had been Jo’s mom she’d been living with for the past six months. Jo’s mom who kicked Dad out of the house. Jo’s mom who seemed so cold and distant and spent twenty-four-seven in the lab.

Jo’s mom. Not her mom.

Which meant her mom was here.

THIRTY-ONE

4:06 A.M.

JOSIE PACED THE ROOM, JO’S SILK PAJAMAS SWISHING with every manic step. Excitement coursed through her body as the pieces of what happened six months ago began to organize themselves in her mind. Things were starting to make sense. There was an answer to her myriad questions lurking just beyond the horizon. She just had to focus and the solution would present itself.

The first piece was obvious. The connection between her and Jo was still strong. Jo could secure the mirror against the basement wall, but she couldn’t close her mind against Josie. Good to know.

Second, the story Nick told her yesterday fit in perfectly with the changes Josie had noticed in her mom. Six months ago, at the same time as the explosion that killed Nick’s brother and left Dr. Byrne supposedly insane, Josie and her dad noticed the change in her mom. Her personality had become harder, less tolerant, less kind. Things she used to love, she suddenly hated. She pulled away from friends. She pulled away from her marriage.

Because it wasn’t her.

What if the explosion in the lab that day had the same effect as the flash from the passing train? What if Josie’s mom and Dr. Byrne created a portal—an earlier portal—and accidentally switched places?

And the mirror. It had been in her mom’s lab for years. What if it had been the portal then just as it was now? The explosion, the flash—the same event that happened to her at the railroad crossing. Maybe it happened that day because it had happened before, zapping Josie’s mom and Dr. Byrne into different worlds? That exact moment in space-time had been weakened, connected to the mirror itself. The catalyst. And when it came in close proximity to trace amounts of ultradense deuterium on the train—the right place at the right time— BOOM! And in the lab in Josie’s basement—BOOM!

The mirror was the catalyst. It wasn’t affected by those explosions; it had been the cause of them.

Josie’s pace quickened. She had to keep moving or she was going to burst.

The mirror was the portal, unstable at first, then strengthening after each explosion until it stayed open for one full minute every twelve hours at the exact moment space-time had been weakened. A hole through which first her mom and then Josie had traveled.

That would explain why her mom was so desperate to get the mirror back. And that would also explain the X-FEL her mom had been cobbling together in the basement. She was trying to re-create the events that led to her being switched in the first place. Her mom was . . .

Josie paused midstep. Not her mom. Jo’s mom. Dr. Byrne.

Because her mom was trapped in this world, locked away in a mental hospital.

Dr. Byrne had been trying to reopen a portal to bring her daughter—her real daughter—through to Josie’s world. And now they were plotting to stay there forever.

Josie took a deep breath. She had a purpose now. It wasn’t just about finding a way home anymore. She had to help her mom. She had to stop Jo and Dr. Byrne before they could destroy the portal and trap Josie in a world overrun with the Nox. She had to re-create Dr. Byrne’s experiment and open her own portal that would send her and her mom home.

She just had one problem. How?

Without thinking, she grabbed her cell phone and dialed Nick.

“Wh-what’s wrong?” Nick said, his voice thick with sleep. “Are you okay?”

“Nick, something happened. A dream.”

She heard rustling on the other end of the line and Nick sat up in bed. “You called me because you had a bad dream?”

“No. I was in Jo’s head. She doesn’t know.” Josie was practically laughing. “She doesn’t know I can still see her in my dreams.”

“What did you see?” Nick said, instantly awake.