"Assuming that's okay with you?" my mother asked, and Macey nodded.

Mr. Solomon stepped away from the door, so like any good operatives (not to mention teenage girls in trouble), we bolted for it.

"Oh, Cammie," Mom called for me, and I stopped while Macey moved on ahead. Mr. Solomon and Aunt Abby followed my roommate outside and closed the door as my mother stepped closer. "Don't worry about Macey, Cam." But it wasn't a soothing phrase. It was an order. "The Secret Service is very good at what they do. For all our differences, my sister is very, very good at what she does. I do not want you worrying about Macey."

"Okay."

"I mean it."

"So do I," I said. And in that moment, I really did.

"I knew you were in the compartment." Macey's voice sliced through the Hall of History. Down in the Grand Hall, girls were eating, people were gossiping, but Macey just sat on the top step looking into the foyer as if she didn't have the strength to stand.

"I didn't hear you or anything," she went on as I walked closer. "It was just a…feeling." Then she looked at me. "You know?"

"Yeah," I said, and I did.

"The top sleeping compartment was hanging too low, and the magazine on the bench had shifted, and I just…knew."

Then she looked at me. "I'm good at this, right?"

"Yeah. You are."

"When your mom called me in, I thought… I thought she was gonna kick me out." She shrugged a little. "Usually that's when I get kicked out."

I've seen Macey without makeup and in her fat jeans. I've heard what she says in her sleep and seen the way her lips move when she's reading and the words just won't sink in. I know Macey McHenry, but that night, sitting on that staircase, I realized I'd never know what it's like to be her.

The McHenrys have five houses, but this is Macey's only home. She's the most famous daughter in America, but Liz and Bex and I are her only family.

"No one's gonna kick you out, Macey." I tried to laugh. "You know too much. By now we'd have to kill you."

It took forty-seven seconds, but eventually Macey smiled. Eventually she laughed.

"So, Preston?" I said, because, honestly, I was sort of about to explode. And…okay … so it had taken me practically twenty-four hours to mention it, but I'd had other things on my mind. Like my sanity, my future, and whether or not Zach's sudden disinterest in kissing had anything to do with the fact that my hair tends to get frizzy when it's raining. But that didn't stop me from leaning closer and whispering, "Did I or did I not hear you kissing Preston?"

"There are people I could hire to kill you and make it look like an accident."

I gripped the banister and propelled myself up a couple of steps. "He's not so bad."

"Seriously. There wouldn't even be an inquest." Macey took a step then added, "Besides, do I have to tell you that secret boyfriends are the hottest?"

In spite of everything, I smiled. "Point taken."

Chapter Twenty-one

I still remember the day—the moment—when I found my very first secret passage. I had been at school three days. My mom had just started her job. My dad had just died. And I'd just arrived at the school I'd heard about my entire life (or, well, the parts of my life that came after the part where I figured out that my mom and dad had more covert reasons for missing my kindergarten graduation).

I was wandering the hallways, wondering about this building that was bigger and older and more beautiful than anything I'd ever seen. Wondering how long it would take for me to realize that my mom would never go away again and my dad would never come back.

Wondering if I really belonged at the Gallagher Academy and if I was truly worthy to carry both the Morgan and Cameron family names.

But then I stopped in the hallway by the library.

A window was open. The school still had the stale feeling of a building that had been underoccupied for a long time, and I watched as a breeze blew through the windows and pushed some dust along the stone-tiled floor, rolling dirt through the cracks like water in a river. But at one point, instead of rolling along, it dropped out of sight as if there were a waterfall in the grout that could barely be seen by the naked eye, disappearing beneath a wall of solid stone.

I pushed and pulled for five minutes before the wall slid open, and I found my first way of disappearing in plain sight.

Three days before I'd found it. Three days I'd been at this place I loved. Three days…

And already I was looking for ways out.

And that was before I was forbidden to leave.

PROS AND CONS OF BEING GROUNDED INSIDE THE MOST AWESOME GROUNDS IN THE WORLD:

PRO: It's a lot easier to protect your roommate from the people who want to kidnap her if she spends most of her time in your room.

CON: When Mr. Mosckowitz asks you to help him proof his paper for the Excellence in European Encryption seminar on Friday night, you can't say "Sorry, I'm going to be out of town."

PRO: Staying out of secret, ancient tunnels means you don't get nearly as many questionable stains on your white blouse.

CON: When your roommate tests a landmark discovery in clean-fuel technology (that happens to reside inside a Dodge minivan), you don't get to ride shotgun.

PRO: You don't have to worry about running into the boy who may or may not have been stalking you.

CON: You don't get to run into the boy who may or may not have been protecting you. (Even though you don't really need protecting, it totally is the thought that counts.)

PRO: You have plenty of time to think.

CON: You don't always like what you're thinking about.

Zach hadn't tried to kiss me.

Of course, there are bigger mysteries in the world, and I'm sure the CIA would have classified that information as a low-level concern (I know … I asked Liz). Maybe it was the way the walls felt close and the grounds felt small, but for some reason that fact kept pressing down on me, day after day.

Don't get me wrong, it's not that I think I'm so completely kissable (because, believe me, I don't), but every morning I walked past the place where he had dipped me in front of the entire school. In the Grand Hall every night I ate in the exact same place where we had danced. And every day, with every step, new questions filled my mind:

• Why had Zach been in Boston (among other places)?

• What had he meant when he'd said that he was someone who didn't have anything left to lose?

• Who had set all this in motion? And why?

For three weeks I wandered the halls, wondering about people who had hurt me and a boy who hadn't tried to kiss me: two great mysteries. But there was only one of them that I had any hope of solving.

"Did you check again?" I asked Liz as we left Culture and Assimilation. "Professor Buckingham told me that MI6 registers a dozen new terrorist groups in their database every week."

"I know," Liz said. "But Cam, there's nothing there. I've run the image of that woman's ring through MI6, MI5, CIA, NSA, FBI. Believe me, if they've got initials, I've hacked them, and that image isn't anywhere."

"I didn't make that symbol up! It's got to exist …" I snapped, but the look that my three best friends in the world were giving made me stop short.

"Cam, darling," Bex said. "Is something…bothering you?"

"Well, I …" I started, but Macey was the one who answered.

"She's still freaked out about Zach."

I may be a pavement artist, but Macey McHenry will always know more about boys and all things boy-related than I can ever comprehend.

"What?" Macey asked with a shrug when I stared at her. "I'm intuitive." She took a step. "Plus, you talk in your sleep."

She was right. Zach and I had fallen out of that train berth together, and the world had been upside down ever since.

"Boys!" I cried, but luckily the halls were loud, and girls were hurrying, and the word got lost in the crowd. Would we ever understand them?

"He can't be…bad?" Liz asked softly. "I mean, didn't we establish last year that Zach is not bad?" She wasn't asking as a girl, she was asking as a scientist who really didn't want to reevaluate her models, duplicate her research, and change any of the things that she thought she'd once proven beyond a shadow of a doubt.

But she hadn't been on the train. She hadn't seen with her own eyes that Aunt Abby knew something about Zach. And Zach knew something about Boston. And someone knew something about that emblem. As Liz started for the labs and Macey started for Encryption, Bex and I boarded the elevator to Sublevel Two, and I couldn't help but ask, "What good is it having elite spying abilities if the people who have the highly classified information are even more elite?"

Bex smiled at me. "Because where would be the fun in that?" The spiraling ramp seemed steeper as it carried us deeper and deeper into Sublevel Two. When we reached the bottom, she stopped and looked at me. "And maybe there are some things"—she spoke slowly, and I knew the words were almost painful as she said—"we aren't supposed to know."

"Motivation," Mr. Solomon said as we settled into our chairs around the old-fashioned tables of the Covert Operations classroom. For weeks I'd been coming to that room, studying our teacher, trying to find some clue in his eyes about Zach and the train and a million other questions that swarmed my mind.

"It's why people do the things they do," our teacher said, the sentence as simple and basic as any lesson we had ever learned; and yet something in Joe Solomon's tone told me it was also the most important.

"What, ladies"—he took a step, scanning the dim room—"is almost always tied to why. There are six reasons anyone does anything: Love. Faith. Greed. Boredom. Fear …" he said, ticking them off on his fingers; but he lingered on the last, drawing a deep breath before he said, "Revenge."

I thought about the people on the rooftop, wondered which of those six things had brought them there. And why.

"We have gadgets," Mr. Solomon said. "We have comms units and trackers and satellites that can photograph the wings of a fly, but make no mistake, we practice a very old art. Six things, ladies. And they haven't changed in five thousand years."

Mr. Solomon turned back to the board. My classmates sat at attention, but my mind was spinning, going over and over what my teacher had just said. I gripped the edge of the table. I saw the classroom fade away. The world came into focus as I said the words, I must have known for weeks but only just realized.

"They're old."

"What are you going on about?" Bex asked. For once in her life she could barely keep up with me as I stepped from the elevator and started up the Grand Staircase.

"We were wrong. I was wrong," I said, the words coming faster now.

"Cam, what—"

"Of course Liz didn't find it in the computer files. Going back fifty years wouldn't help. Going back a hundred wouldn't help. Bex, they're not a new threat!"

In the foyer below us, girls were going in for lunch. The halls were alive with the smells of lasagna and talk of midterms, but my best friend and I were alone in the Hall of History as I pointed to our school's most sacred treasure.