As we walked between Madame Dabney's tea room and the elevator to Sublevel One, Tina Walters told me for about the tenth time, "Cammie, you don't even have to steal the file…Just take a little—"

"Tina!" I snapped, then whispered because a crowded hallway full of future spies isn't the best place to have a covert conversation, "I'm not going to steal Macey's permanent record just to see if she really set the gym on fire at her last school."

"Borrow," Tina reminded me. "Borrow the permanent record. Just a peek."

"No!" I said again, just as we turned into the small, dark corridor. I saw Liz standing there, staring into the mirror that concealed the elevator as if she didn't recognize her own reflection. "What's wrong with …" Then I saw the little slip of yellow paper. "What? Is it out of order or—"

And then I read the little slip of yellow paper.

SOPHOMORE C.O. CLASS CANCELED.

MEET OUTSIDE TONIGHT. 7:00,

DON'T WEAR YOUR UNIFORMS!

-SOLOMON

Bex's reflection appeared beside mine, and our eyes locked. I started to rip the note from the mirror, to save it as a piece of Gallagher Academy history, because two things were extraordinary about it. First, I'd never even heard of a class being canceled, much less witnessed it myself. Second, Joe Solomon had just invited fourteen girls to go on what amounted to a moonlight stroll.

Things were about to get interesting.

I've seen Liz freak out about assignments before, but that day at lunch, she was as white as the salt in the shaker as she went over every tiny, perfectly punctuated line of her CoveOps notes—stopping occasionally to cinch her eyes together as if she were trying to read the answers on the top of her head. (Maybe she was. With Liz's head, anything is possible.)

"Liz, est-ce qu-il-y-a une épreuve de CoveOps dont je ne connais pas?" I asked, thinking that if there was a CoveOps test I didn't know about, someone should really bring me into the loop. But Liz thought I was trying to be funny.

"Tu ne la considéras pas sérieuse?" she nearly yelled. "Tu sais ques Ke qui se passe ce soir!"

Of course I was taking it seriously, but Liz wasn't about to believe that, so I abandoned our French assignment and whispered, "No, Liz, I don't know what's going to happen tonight."

"Exactement!" she cried, leaning closer. "Anything in these books could be out there!" she said, as if we were dropping into an actual war zone and not our own backyard. "Or it could be something"—she looked around and then leaned closer—"not in the books!"

I seriously thought she might throw up, especially when Bex leaned over and said, "I bet we're going to bust up a drug cartel that's operating out of a nightclub." (Because she saw that once on an episode of Alias.)

Liz gulped, and her knuckles went white as she gripped a flash card. "It won't be anything like that, Liz," I whispered. But by this time the entire sophomore class was staring.

"Why?" Tina demanded. "What do you know? Did your mother tell you something?"

"No!" I said, wishing I hadn't gotten them started. "I don't know anything."

"So Solomon didn't ask your mother for two helicopters, three stun guns, and a dozen Brazilian passports?"

But before I could respond to Tina's ridiculous question, the main doors opened, and the seventh-grade class came in, doing a lot of bon jouring—"hello" being one of the few phrases they knew—and the sophomore class forgot about me and went back to doing what it had been doing for a week—watching Macey McHenry.

She was the first person to ever combine black fingernail polish with a Peter Pan-collared white blouse (that's not verified or anything—just a guess), and her diamond nose ring looked like a twenty-thousand-dollar zit, but to an outsider, Macey McHenry might have seemed like one of us. She walked through the Grand Hall like she owned the place (as usual), picked up a plain green salad with no dressing (as usual), and walked to our table. Then she plopped down next to Bex and said, "The munchkins annoy," which was totally not usual.

Up to that point, I'd mainly heard Macey say things like "You're in my light," and "If you're gonna have plastic surgery, you might want to try my mother's guy in Palm Springs." (Needless to say, Mr. Smith didn't write down the number.) But there she was, sitting with us, talking with us. Acting like one of us!

Liz said, "Je me demande pourquoi elk a décidé a parler à nous aujourd'hui. Comme c'est bizarre!" But I didn't know why Macey was feeling so talkative, either.

Before I could respond, Macey turned to Liz and snapped, "I don't want to talk to you either, freak."

I was just starting to process the fact that even cosmetic heiresses who get kicked out of a lot of private schools speak pretty good French, when Macey leaned closer to Liz, who leaned away.

"Tell me," Macey said in the worst imitation Southern accent I've ever heard, "how can someone who's supposed to be so smart sound so stupid?"

Liz's pale face turned instantly red as tears came to the corners of her eyes. Before I knew what was happening, Bex had flown from her seat, pinned Macey's right arm behind her back with one hand, and grabbed that diamond nose ring with the other so fast that I said a quick prayer of thanks that the British are on our side (well, assuming we never revisit the Revolutionary War).

"I know you're three years late, but let me give you a real quick, important lesson," Bex said in English (probably because it's harder to sound scary in French). But the strangest thing was happening—Macey was smiling—almost laughing, and Bex totally didn't know what to do.

The rest of the hall was going slowly quiet, as if someone somewhere was turning the volume down. By the time the teachers stopped talking, Bex still had ahold of Macey, I had leaned across the table to grab ahold of Bex, and Liz had a death grip on a flash card that listed the top five places you should go to look for black market explosives in St. Petersburg.

"Rebecca," said a male voice. I turned away from the tight-lipped smirk that was spreading across Macey's face to see Joe Solomon standing behind me, speaking across the table to Bex, who was slowly allowing blood to creep back into Macey's arm. "I understand you could get into trouble for that," he said.

It's true. Gallagher Girls don't fight in the hallways. We don't slap and we don't shove. But mostly, we don't use the skills of the sisterhood against the sisters. Ever. It's a testament to how universally despised and viewed as an outsider Macey was that Bex wasn't immediately jumped from ten directions. But Mr. Solomon was an outsider, too. Maybe that's why he said, "If you're so eager to show off, you and your friends can take point tonight." He looked at Liz and me. "Good luck."

It wasn't a cheery, break-a-leg "good luck," though. It was a watch-out-or-you'll-have-your-legs-broken "good luck."

Liz went back to her flash cards, but Bex and I stared at each other across the table as our faces morphed from sheer terror to uncontrolled excitement. For Gallagher Girls, leading a mission is no punishment—that's the gold-freaking-star! Only a little of the dread lingered in the back of my mind as I realized that we were about to play with live ammo— maybe in both the literal and figurative senses of the word.

Macey returned to her salad while Mr. Solomon added, "Et n'oubliez pas, mesdemoiselles, ce soir vous êtes des civils— ressemblez-y."

Oh, yeah, just what I needed—fashion advice from Joe Solomon himself. The Grand Hall went back to normal, but I doubt that any of the sophomores, besides Macey, took another bite. As if we hadn't known it before, Joe Solomon had just reminded us that we'd soon be venturing out from behind our comfortable walls, operating on our own for the first time in our superspy lives.

Four years of training had all come down to this, and I for one didn't have a thing to wear.

I'm not sure how it happened, but at some point between one P.M. and six forty-five, the sophomore class from the Gallagher Academy for Exceptional Young Women morphed from a group of spies-in-training into a bunch of teenage girls. It was pretty scary.

Liz spent her afternoon becoming the textbook version of what an undercover operative should look like, copying everything from the patent leather purse to the pillbox hat. (It was a pretty old textbook.) Then the hallways started reverberating with terrifying yells of "Have you seen my black boots?" and "Does anyone have any hair spray?"

I was seriously starting to worry about the fate of national security. In our suite, Bex looked awesome (as usual), Liz looked ridiculous (but try telling her that), and Macey was looking at an old Cosmo as if determining whether green is the new black was a matter of life or death. All I could do was sit on my bed in my old jeans and a black knit top my mom once wore to parachute onto the top of the Iranian Embassy, and watch the clock tick down.

But then Tina came busting into our room. "Which one?" she asked, holding a pair of black leather pants and short skirt in front of her. I was on the verge of saying, neither, when Eva Alvarez ran in.

"Do these go? I don't know if these go!" Eva held up a pair of high-heeled boots that made my feet hurt just by looking at them.

"Um, Eva, can you run in those?" I asked.

But before Eva could answer, I heard someone say, "They're all the rage in Milan." I looked around. I counted heads. And then it dawned on me who was speaking. Macey stared at us over the top of her magazine, and added, "If you want to know."

Within minutes, half the sophomore class was in our little suite, and Macey was telling Tina, "You know, lip liner is supposed to go on the lips," and Tina was actually listening! I mean, this is the same girl who had single-handedly started the Macey-is-Mr. Smith's-illegitimate-daughter rumor. Little did we know she was one fashion emergency away from turning to the enemy!

Courtney was borrowing earrings; Anna was trying on jackets; and I wasn't sure if I would ever feel safe going into hostile territory with any of them ever again.

"You know, Eva, what blends in Milan might stick out in Roseville," I tried, but she didn't care.

"You know, guys, hiding in plain sight requires looking plain!" I said, but Kim Lee was wriggling out of a halter top and nearly knocked my head off with her flailing arms.

"You know, I really don't think he's taking us to the prom!" I shouted, and Anna put Macey's gorgeous formal gown back into the closet.

I'm the chameleon! I wanted to cry. I'm the CoveOps legacy! I'd been preparing for this night my entire life—doing drills with my dad, asking my mom to tell me stories, becoming the girl nobody sees. But now I was drifting deeper and deeper into the shadows until I was standing in the middle of my own room, watching my closest friends swarm around our gorgeous new guest, and I was completely invisible.

"Lose the earrings," Macey said, pointing to Eva. "Tuck in the shirt," she told Anna, then turned to Courtney Bauer and said, "What died in your hair?" (Courtney does have a tendency to over-gel sometimes.)

Bex was sitting with Liz on her bed, and they both looked as amazed as I felt.