"You weren't supposed to trust him," Jo said. "He's known about the portal all along. About you and about my mom. He's the one who made me switch places with you, to try and find the injectable my mom supposedly brought with her when she accidentally zapped into your world. What he wants more than anything"-she pointed to the vial on the bed-"is that. He'll do anything to get it."

"He was the traitor. He sabotaged your mom's experiment. He was going to sell the formula to the Grid."

"Exactly. He'll kill anyone that gets in his way," Jo said. "Anyone."

Josie's mind whirled. She could go to the authorities with what she knew, show the antidote, and hope someone would actually listen to her, but that seemed unlikely at best.

No, there was only one way to get her friends and family back. One thing Mr. Byrne wanted more than anything else.

The vial.

"Jo," she said. "Would your father really kill anyone who got in his way?"

"Without blinking an eye," she said.

"Even you?"

Jo looked confused by the question. "I-I don't know."

"Do you want to save Nick?"

The mention of Nick's name seemed to brace Jo's courage. "Yes."

"Then let's find out how far Daddy would really go." She pulled out her cell phone, dialed Mr. Byrne's number, and handed it to Jo.

"What are you doing?"

"Just act like you're on his side. That you've caught me and have the vial. I'll prompt you."

Mr. Byrne answered on the first ring. "Princess!"

"Save it, Daddy," Jo said. "It's me."

"Jo?" He sounded genuinely surprised.

"Of course." She glanced up at Josie and covered the mouthpiece.

"Tell him you came back to find the injectable," Josie whispered.

"I came back," Jo started. Her acting skills were impressive. She sounded cold and confident. "Like you told me. Mom doesn't have the vial."

Josie gave her the thumbs-up.

"Doesn't matter now," he said. All the fake warmth had vanished from his voice. "I've got everything I need."

"Not everything," Josie whispered.

Jo echoed her. "Not everything."

"What do you mean?" Mr. Byrne snapped.

Josie held up the vial.

"Josie had the original vial," Jo said. "I've taken care of her. I have the antidote now."

"Well, well, well," Mr. Byrne said. "I guess you're my daughter after all."

"Ask to exchange it for Nick," Josie whispered again, lower this time.

Jo nodded. "More than you know. I have what you want, and you have what I want."

Mr. Byrne laughed. "The boy?"

"Yes."

"I thought I taught you to think bigger than that."

Jo didn't take the bait. "Do you want to make the exchange or not?"

There was a pause before Mr. Byrne spoke again. "Where did I take you for your seventh birthday?"

Jo winked at Josie. "That's a trick question. You never took me anywhere for my birthday. Parties make you weak."

"Very well," he said slowly. "If you want the boy, you can have him. Meet me at my office at dawn."

FIFTY-TWO.

6:15 A.M.

THE PLAN WAS RELATIVELY SIMPLE. JOSIE WOULD pretend to be Jo and confront Mr. Byrne in his office, and Jo would try and find the hostages and lead them to safety. It wasn't a great plan, but at least the blush of sunrise was starting to spread its way westward across the sky. That meant they wouldn't have to worry about the Nox. Point in their favor.

"There's a massive lab complex on the third floor," Jo said as she drove her BMW to her dad's office, proving to be more helpful than Josie could possibly have imagined. "If he's got them working on the antidote, that's where they'll be."

"Perfect." Josie handed her Nick's gun. "You get them out of there, and I promise I'll save Nick for you."

Jo looked at the gun in her lap, then up at Josie. "For me?"

Josie's heart felt like it was being squeezed by a vise. "He's part of your world, Jo," she said, her mouth dry. "Not mine."

Jo nodded but didn't say a word.

They pulled into the brightly lit parking lot where Nick's SUV was parked between two large, black Suburbans. "Any idea who that might be?" Josie asked.

"They're company cars," Jo said. "One might be my dad. Not sure about the other."

Josie sighed. She'd known this was a long shot, but she'd been hoping to find Mr. Byrne alone. Oh well. If she was going down, she was going down fighting. She just prayed her dad and Penelope had managed to free the mirror. At this point, it might be their only way home.

"My dad's office is on the fourth floor," Jo said. "Northeast corner."

Josie nodded. "You go first. If he's watching security footage, hopefully he'll stop once you enter the building. I'll follow right behind. You head straight for the lab and I'll deal with your dad."

"But how am I supposed to fit all those people in this car?"

Josie had no idea. She didn't even know if there'd be anyone in there to save. Instead of answering, she gave Jo a weak smile. "Good luck. I'll meet you back at the house."

Josie watched from inside the car as Jo walked to the front door. Blood thundered in Josie's ears. They were walking into a trap-that she knew. But even if she didn't make it out, she hoped the others-Madison and Jackson, the Kaufman twins, even Josie's mom-might make it to safety.

Jo had a conversation with someone over the intercom, the door buzzed, and she pushed it open. As she walked through, she jammed a wad of paper into the locking mechanism as she and Josie had discussed.

As soon as Jo was out of sight, Josie sprinted across the parking lot to the front door, praying the wad of paper had prevented the lock mechanism from latching back into place. She tensed as she pushed the handle.

The door swung open without a sound.

Well, at least that had worked.

Josie held her head high and tried to look as arrogantly sure of herself as possible as she pushed the elevator button, just in case anyone was watching. Maybe having two Jo Byrnes in the building would at least confuse people long enough to give Josie a chance to get away. Maybe. The door slid open immediately, and Josie stepped inside, pressing the button for the fourth floor just as Jo had told her.

Mr. Byrne's office was at the end of the hall. Josie had half expected him to meet her at the elevator door, but the hallway was deserted. She walked slowly down the hall; the squeak of her Converse against the highly polished floor echoed through the deserted corridor. At least she wasn't trying to surprise anyone. That wouldn't have worked out so well.

She knocked on the door at the end of the hall and waited. No answer. She was about to knock again when she realized that Jo wasn't exactly the polite type. And she was Jo, after all. Josie took a deep breath, threw her shoulders back, and marched into the office.

Josie wasn't sure what, exactly, she thought she'd see in Mr. Byrne's office. An oversized wooden desk with a leather executive chair, awards and degrees mounted on the wall, and photos of Mr. Byrne with dignitaries and celebrities displayed on a bookcase. That seemed like standard high-powered executive digs to her. But what she found was a laboratory, all high-tech and stainless steel, with a modest architect's desk facing the window and a cluster of white armchairs in the corner, set up around a short conference table.

Mr. Byrne was a scientist? That seemed so out of character.

She scanned the room, looking for any sign of Mr. Byrne or Nick. She stepped farther into the room. "Daddy?" she said forcibly. "Where are you?"

A sound from the back of the room made Josie turn. There were three doors, and beside each was a large viewing window. Two of the windows were completely dark; the third was lit from within. Through the window, slumped forward in a metal chair, she saw Nick.

Josie wasted no time. She sprinted down the length of Mr. Byrne's lab-slash-office and yanked at the door. She hadn't expected to find it unlocked, but the door whipped open.

Nick's face was scratched and bruised. His right eye was already half-closed with heavy swelling, and his lower lip was cut in two places. Blood stained his shirt, but when his head snapped up as the door opened, Josie saw that his face was defiant and angry. As soon as he saw Josie, a look of fear washed over him.

"Josie," he said. "Get out of here. It's a trap. It was Mr. Byrne all along."

A lump rose in Josie's throat. He'd been beaten and tortured, all because she insisted they trust Mr. Byrne. She ran to him, caressing his cheek, then ducked behind him to try and untie the ropes that bound him to the chair.

"I'm so sorry," she said, struggling with the knots.

"Leave me," he said. "Just get out of here. He's got Nox in the other rooms. He likes to watch through the windows while they torture and kill people."

"Almost got it."

"He can't catch you here, Josie. He can't. I couldn't bear it."

With a final tug, Josie loosened the ropes and Nick tipped forward in his chair. She grabbed him around his waist and held him back, keeping him from falling on his face. He was so weak. Whatever Mr. Byrne had done to him, it was all Josie's fault.

Nick sat there panting for a moment, then caught his breath. "I'm okay." He pushed himself into a standing position, and grabbed Josie's hand. "Come on. Let's get out of here."

They stepped out of the cell and froze.

Mr. Byrne stood in the doorway, blocking their only exit. He held Nick's gun in his hand, pointed right at them.

FIFTY-THREE.

6:37 A.M.

MR. BYRNE'S ENTIRE DEMEANOR HAD CHANGED, and Josie wondered how she had ever seen kindness in that face. The soft eyes and sad smile had been replaced by a steely glare and lips pressed firmly together in a determined line. There was a gauntness about his cheeks, sunken and sallow; yet far from appearing tired or drained, he had an uplifted energy about him, as if the death and destruction he'd put into motion in the last twenty-four hours actually invigorated him.

The silence of the room was oppressive as Mr. Byrne stood before them, coolly assessing the situation. The hum of the overhead lights seemed louder now, more intense. Everything was heightened around her. Even the sound of Josie's own breathing sounded like it was amplified through a loudspeaker.

"It was a nice try," Mr. Byrne said at last. "Using my daughter as a decoy. For a moment, I almost thought she was you."

Josie tried to sound brave. "Where is she? What have you done with her?"

Mr. Byrne clicked his tongue. "I'll deal with her later." He nodded at Nick. "And your brother. Right now it's your turn."

Nick stepped to his right, attempting to shield Josie from the gun pointed at her. For a moment, Josie almost laughed. It hadn't been that long ago that Nick had been the one holding her at gunpoint with that exact same weapon.

"What do you want?" Nick said. He reached behind his back and grasped Josie's hand firmly.

Mr. Byrne smiled without a hint of mirth. "That's funny."

Nick squeezed Josie's hand. "We're just trying to get Josie home. That's all."

"Of course you are." His words dripped with sarcasm. "You're not trying to smuggle the vial out of here at all, right?"

Nick squared his shoulders, as if preparing for a blow. "I don't know what you're talking about."

"Sure you don't." Mr. Byrne reached his free hand to the wall and pressed a button. Above the exterior windows, a blackout curtain slowly descended. "I can just shoot you both and rifle through your bodies later. Or let the Nox have at you like I did with your friend and her father." There was a cold-bloodedness in his voice that made Josie's skin crawl. "Her death was anything but quick and painless."

Josie started, but Nick tightened his grip on her hand. If Mr. Byrne was going to shoot her, she at least wanted to get a running start and maybe get one decent swipe at his face before the life drained out of her body. That would almost be worth it.