“They got away,” a man’s voice said from inside the lab.

“You!” someone else shouted—an order, “Take a team to sweep the perimeter. Make sure they don’t get too far. But suit up, and be careful. These kids are dangerous. I don’t want any Code Reds on my watch.” My skin crawled with recognition. The voice . . . the man giving the order, I knew it. It was him . . . Agent Truman.

“Sir, there aren’t enough bio-suits for everyone,” the other man responded.

There was a pause, a heavy, thought-filled pause, and then Agent Truman answered, “So pick your best men and suit them up. We need to shut this down. And fast.”

My eyes went wide as a flurry of activity came from inside the lab and then it grew somewhat less frantic.

He was here. Agent Truman was here, right on the other side of that wall. My head swam as I considered just how close he was. How easy it would be for him to find me. To capture me.

Not only that, they knew it was us they were after.

“We have to go!” I half mouthed through the semidarkness. “There,” I said, pointing because Jett hadn’t been wrong about that human-flashlight thing. Here, I definitely had the advantage.

Ahead of us, there was a staircase. I had no idea where it led, except down. But since our alternative was to turn ourselves in to those Daylighters in the lab, I figured it was worth a shot.

The moment I started toward it, Simon reached for me, and, feeling somewhat smug to have the upper hand, I repeated the words he’d used on me back in the lab: “It’s okay. Trust me.”

I half worried Simon would trip since the stairway was so steep and I was practically running down them. When we reached the bottom, I glanced around wishing I’d spent more time studying Jett’s blueprints.

It was as if we’d entered a giant hamster maze, those colorful plastic ones you find at pet stores. Except instead of being plastic and colorful, like the hamster tubes, the ducts we were standing in were industrial and metal and supersized. We wouldn’t have to crawl on our hands and knees.

It was the sound that made me realize what this was: the kind of ductwork that circulates air through office buildings, the constant whoosh-whoosh. And I was right, there were fans every twenty paces or so all along the corridor behind these enormous screened openings—even bigger than the one we’d crawled through. And when we rushed past them, which we did because the sensation of being sucked at creeped me out, the whooshing sound grew louder and my hair whipped my cheeks.

I leaned close to Simon’s ear so he could hear me, and I still had to shout. “What now?”

“Keep going!” Simon yelled back. “And if I give you the word, then whatever happens, don’t breathe!” He said the last two words super slow, making sure I knew this part was extra important.

Like instructions: Don’t breathe.

“What’s that supposed to mean?” I asked. “What word?”

He just repeated himself. “The word.” And before I could ask again, he shoved me. “Go, Kyra. We don’t have time for this.”

Yes. Right. No time. The throbbing noise of the fans had me rattled, but I didn’t need to be reminded why we were running: I was sure that the others—not the good-guy others of our team, but the bad-guy ones—would be right behind us any second, and I hurried to get past the next vent.

The tunnels felt endless, and there were several places where we had to make a decision to go left or right. I was the one who could see, but it was Simon who made the call. I got the sense that he understood this place, and the layout of it, far better than I’d realized. As if he’d not only studied the schematics, but that he’d committed them to memory.

The ceiling never got lower, but the passageways definitely got narrower, and it was the narrow part I wasn’t thrilled with. I wasn’t crazy about narrow. It wasn’t that I was claustrophobic per se, at least not in the sense that I was going to have a full-on panic attack or anything, but I definitely wasn’t in love with confined spaces.

I guess you could say I was claustrophobic-light.

Just knowing that Simon was already blocking my escape route going back made my heart trip over itself whenever I spent too much time thinking about it. And the farther we went, the more reckless it beat as this awful feeling that these tunnels might never, ever end became something heavy and solid and real.

Then something snared me, strong fingers seizing me, pinching the bones of my wrist, and I jolted backward. My breath caught hard in my throat. If Simon hadn’t been there, still blocking my exit, I would have fallen over for sure.

“GO!” I shouted, trying to shove Simon out of my path, but I was already being dragged toward whoever had ahold of me.

The man appeared then, coming out from where he’d been hiding, waiting for us, I was sure, in an opening in the passageways. I could see him as clearly as if it were daylight, and it was my second polar-bear moment of the day.

“Gotcha,” he growled, looking more military than Agent Truman ever had, right down to the black grease paint smeared across his sharp features. He wasn’t suited up, which was a scary thought, because if this guy wasn’t one of Truman’s best, then I definitely didn’t want to run into one of the suited-up dudes!

His eyes were a shade of blue so pale they were virtually colorless and downright chilling. I could almost imagine that even his teeth, if he were to show them to me, would be polar-bear sharp. He raised his hand and before I realized what was happening, there was a flashlight shining directly into my face.