There are many things I love about the P&E barn, like the way the light filters through the skylight, and how sometimes in winter birds nest in the rafters and you can hear chirping and singing in between all the grunts and kicks. (I don't necessarily like the landing in bird poop part, but that's just another incentive to keep you on your feet.) That day, however, the thing I loved most about the P&.E barn was that it's a place where you're allowed—even expected—to hit people.

"You liar!" I yelled as I walked into the barn. Light bathed the old timbers, and the whole room seemed to glow.

But Zach just stopped punching the heavy bag for a second and said, "Spy," as if that made everything all right. Which, let me tell you, it didn't.

First, there was the fact that he'd lied to a member of the sisterhood, and even though he technically isn't a sister, that is simply not done. Plus, there was the fact that he'd completely humiliated me in front of the entire school.

And then there was the thought that had haunted me all the way from the Grand Hall to the P&E barn. Either Zach didn't want to admit to being alone with me, or he knew more about what had happened last night than he was willing to admit. At the moment I don't know which answer I preferred; all I really knew was that, in either case, Zachary Goode had something to hide.

His fists were sure and steady as they beat the heavy bag. Small beads of sweat ran down the side of his face and onto the mat beneath us.

"Zach!" I yelled as if maybe he'd forgotten I was there. "You know I didn't breach security last night. You know I didn't cause the Code Black."

He looked at me and said, "Oh, I thought it was a false alarm," in the manner of someone who didn't think it was a false alarm at all.

I hit the bag with all my might, and Zach raised his eyebrows. "Not bad." He stepped around to hold the bag. "Put your shoulder into it now."

"I know how to do it," I snapped.

"Do you?" he asked, smiling that same winking, mocking smile. And then, I don't know if it was nerves or PMS or just the fury of a woman scorned, but I hauled off and kicked the heavy bag—hard—and it flew back and hit him in the stomach. For a second he stood there, doubled over, trying to catch his breath. "Nice one, Gallagher Girl."

"Don't call me—"

"Look," Zach cut me off as he stepped around the bag and placed his hands on my shoulders. "Do you really want everyone knowing we were together?" He paused. "Do you think that maybe what happened last night isn't any of Tina Walters's business?"

Honestly, twenty-four hours earlier I would have hated the thought of Tina Walters thinking that Zach and I were off somewhere together, but everything looks different after you've seen the world go black.

"Besides," Zach said as he smiled and wiped sweat from his upper lip with the back of his hand, "I thought you liked your interludes secret and mysterious. Your boyfriends private."

"We weren't having an interlude. And you are not my boyfriend."

"Yeah." He hit the bag harder. "I noticed."

"What's that supposed to mean?"

Zach stopped. The bag swung back and forth, keeping time as he shook his head and said, "You're the Gallagher Girl. You figure it out."

Boys! Are they always this impossible? Do they always say cryptic, indecipherable things? (Note to self: work with Liz to adapt her boy-to-English translator into a more mobile form—like maybe a watch or necklace.)

"Besides," Zach said, "at my school, we learn how to keep a secret."

"Yeah. I know. I go to a school like yours."

He looked at me. "Do you?"

I've found a lot of secret passageways in my time as a Gallagher Girl. During my seventh grade year I was almost always covered in dust and cobwebs as I pulled levers and pushed stones until I unearthed a version of my school that probably hadn't been seen since Gilly herself had roamed our halls. But when I'd found the narrow tunnel that led to a hidden room outside my mother's office, I'd kind of made an unspoken promise to myself that I wouldn't use it—that I'd never eavesdrop. But that night felt like an exception.

Dust hung heavy in the tunnel. My shoulders grazed old stones and rough wooden beams. Light fell through gaps in the stones as the passageway widened, and soon I was looking for my mother through the cracks—but seeing Mr. Solomon. "Do you think any of the girls have guessed?" he asked.

"About Blackthorne?" Mom asked, and Mr. Solomon nodded.

"No. But if one of them knew the truth, then they'd all know the truth."

Mr. Solomon laughed. "You're probably right." He straightened out on the couch. "You still think this is a good idea?"

Mom walked to her desk. "It's what we have to do." She turned and looked into the distance. "For everyone."

On the way to our suite I avoided the busy staircases and crowded hallways—not because of the stares and whispers, but because I wanted to think about the way Zach looked during the Code Black; I wanted to remember the long, quiet ride from D.C. and my mother's worried face. And more than anything, I wanted to ask myself the question that had been looming in the back of my mind since I'd first seen Zach in D.C.: Who were those boys, really?

All we had was a picture of Mr. Solomon in a T-shirt and my mother's word that we needed to forge friendships for the future. That didn't change the fact that the Gallagher Academy hadn't had a Code Black since the end of the cold war—until they showed up. That didn't change the fact that Zach had looked Tina in the eye and lied.

Twenty-four hours before, I'd stood in that cold, empty corridor and thought that Zach knew me; but I didn't know him. I didn't know any of them. And I didn't like it. At all.

I pushed open the door to our suite and announced to my roommates, "We've got work to do."

Chapter Nineteen

I know what you're thinking. And the truth is, I might have thought it, too. I mean, it's not like we had a lot of free time on our hands and were looking for an extra project. It's not as if I enjoy getting summoned to D.C. and debriefed by the CIA. I don't go looking for trouble, but I couldn't shake the feeling that trouble might have found us—walked through our front gates and moved into the East Wing. So even though there were about a million reasons to forget the whole thing … we didn't. Instead we waited, and we watched, and a week later we were ready. Sort of.

"Tell me again why this isn't an incredibly bad idea," I muttered in the dark passageway. Cobwebs clung to every inch of me. My equipment belt was on too tight, and Liz kept stepping on my heels and making high-pitched squeaks (everyone knows she's afraid of spiders).

"Well, I think it's bloody brilliant," Bex replied. It was also bloody risky, and that, I knew, was part of its appeal for Bex.

I hadn't meant for it to come down to this. Seriously. I thought we might look up their birth certificates or do other least-intrusive-means-necessary things. But as I stood in the secret passageway that led to the East Wing, I couldn't help but feel pretty intrusive.

"Guys, maybe breaking about a dozen rules isn't a good way to … you know…prove I didn't break any rules," I suggested.

But Bex just smiled through the dusty dim light. "It is if we don't get caught." She stepped over one of the thin motion-sensing lasers that the security department must have installed over winter break. "And I don't plan on getting caught."

I stopped in the corridor, felt Liz, then Bex bang into me as I listened for something—anything—to give us an excuse to turn around.

"But what if they aren't really gone?" I asked.

"They are," Bex said.

"But shouldn't we wait? We've only had a week of prep work. We don't know their patterns of behavior yet. We don't—"

"Cam, I told you," Liz said. "Dr. Steve is making the boys do some kind of group-bonding thing. It has to be tonight."

And she was right, as usual—but that didn't make me feel better.

Summary of Surveillance The Operatives undertook a high-risk operation that could lead to answers … or expulsion … or both.

"Don't worry, Cam," Bex whispered. "It's not that different from when we broke into Josh's house."

I crouched at the air vent that would take us into the boys' rooms and reached for the tiny bottle of hair spray that I keep for emergencies (just not of the hair variety) and sprayed the area around the grate. A grid of tiny motion detectors flickered in the fumes.

"Yeah," I whispered. "Just like Josh's."

Liz hooked a device up to the laser circuits, and I watched the red beams disappear. Then there was nothing standing between us and the forbidden wing—between us and possible answers.

But here's the thing about black bag jobs. 1) You don't actually have to carry a black bag to break and enter and obtain covert information (even though they do come in handy). And 2) No matter how clear your objectives, you're never one hundred percent sure what you're looking for. After all, it might have been nice to find a file labeled TOP-SECRET PLAN TO INFILTRATE AND DESTROY THE GALLAGHER ACADEMY, but I would have settled for some clue about the boys who now shared our classes; I would have been happy with a snapshot that showed me the real Zach Goode.

As we slid through the vent and dropped to the floor of the common room, Bex said, "Okay, Liz, start on the computers. Cam, you and I can…" But then she trailed off. She stopped and stared. The three of us had officially gone where no Gallagher Girl had ever been before, and standing there, I couldn't shake the feeling that nothing in our training had prepared us for … that.

We'd been to these rooms only weeks before, but everything seemed smaller now. Greener, too (but that's probably because we were wearing night-vision goggles). And…

"Oh. My. Gosh." For the first time I couldn't fault Bex for being overdramatic.

Moonlight fell through the windows. Someone had left a desk lamp shining in the corner of the room. I pulled off my goggles, letting my eyes adjust to the dim light as I looked around the room. Liz's hopes of scientifically analyzing typical teen-boy behavior was going to have to wait, because one look at this space was enough to tell us that these were not typical boys.

"Are all boys so …" Liz started, but couldn't seem to find the words to finish.

"Clean?" Bex suggested, sounding pretty disgusted, because (take it from someone who has lived with her for four years) no one appreciates the "lived-in" look more than Rebecca Baxter.

There were eight suites, where we found freshly shined shoes and beds made with hospital corners. Books and notebooks were stacked neatly on desks. There were no socks on the floor; no girlie calendars or back issues of Sports Illustrated. It seemed more like the barracks of soldiers than the rooms of boys, and I instantly regretted leaving Macey outside to serve as our lookout, because if we'd ever needed the Gallagher Academy's resident boy expert, that was the time.

Everything was temporary. And sterile. And with every step I felt more sure that the Blackthorne Boys were simply passing through. Which was both a little comforting—and a lot confusing. Why were they here?