"Liz," I snapped, "protocol says that we're supposed to report any suspicious activity to the security department immediately! We were being tailed in Roseville!" The words felt heavy. "And Zach recognized one of them." I took a deep breath before I finished, "And he lied to me about it."

I remembered the expression on my mother's face as we'd sat in the red glow of the emergency lights during the Code Black. Someone or something had already threatened our school once this semester, so I didn't worry about Zach's feelings or what Madame Dabney would say about leaving a boy during the middle of a date. I didn't ask my friends if they knew the reasons why a boy might try to kiss a girl, and all the reasons a girl might let him.

We'd had a tail in Roseville—that was all that mattered. I felt my feet pounding the pavement. As we reached the mansion, I finally turned to see almost the entire sophomore class running down the lane behind me. "You were right," Courtney told us, swallowing hard, gasping for air. "We had a tail, too."

And whatever hope I'd had that I was wrong—that it was all some bizarre misunderstanding—vanished in the wind.

We pushed open the mansion's doors, and I immediately felt the silence that's usually reserved for the days before classes start and after they end, when I'm the only Gallagher Girl there to roam the halls.

"Mom!" I called, but my voice echoed in the empty corridors.

Courtney and Eva went into the Grand Hall. Mick and Tina started for the library. I headed for the Hall of History.

"Mom!" I called again, but my voice was swallowed by screeching sirens as the lights went out and the words "CODE BLACK CODE BLACK CODE BLACK" filled the air.

Gilly's sword disappeared into its impenetrable case, the bookshelves around us became vaults, and metal shutters covered the windows.

"Cammie!" Bex called over the sounds of the sirens and my raging thoughts. "Cammie, come on!"

My best friend took my hand and pulled me toward my mother's office, but my mother wasn't there. No one said, "Hey, kiddo," and no one told me everything was going to be okay.

We turned and ran down the Grand Staircase while the mansion transformed itself into a tomb.

"Cam, where's your mom?" Liz said, as if I knew but wasn't telling.

"Where are the teachers?" Bex said, spinning, looking in every direction. Tina and Eva came running down the hall. Mick, Kim, and Courtney came out of the Grand Hall. Soon, almost the entire sophomore class was standing in the echoing foyer, but there were no teachers. No guards. The entire school must have been out, savoring their freedom in Roseville. We seemed to be entirely alone.

Then I saw a shadowy figure moving down the hall, stumbling, holding the wall to support himself.

"Mr. Mosckowitz?" Liz yelled, then rushed forward with Bex.

Our teacher fell into their arms. Blood stained the side of his face, and his voice was faint as he lay on the floor and said, "He got it."

"Got what?" I asked through the roar of the sirens.

"The list—a disc with the alumni list." He sat up and gripped my shoulders. "He got it. And it's…out there."

And then Mr. Mosckowitz passed out cold.

It's easy to look at the Gallagher mansion with its tall stone fences and ivy-covered facade and imagine the riches it must hold. Even people who know the truth about who we are and what we do probably think about the science labs where some of the world's greatest inventions have been born. Our library has been described as priceless. Still, our most precious resources aren't behind our walls at all—they're out in the world. Undercover. The real legacy of the Gallagher Girls lives not behind stone and glass but in flesh and blood. The other stuff—that's just for burn bags.

As we carried Mr. Mosckowitz to a cushy chair and checked his pulse, I couldn't shake the feeling that an entire sisterhood was riding on our shoulders.

The last rays of sunlight were disappearing from the mansion, so Tina pulled a lantern from the wall and struck a match. "Will somebody please tell me what's going on?" she demanded in frustration.

"The boys," I said. Even in the dark I could feel my friends looking at me, soaking in my every word. "Zach lied about seeing a tail in town—tails that were probably there to make sure we didn't come back too soon."

"And Mr. Mosckowitz said he got the disc," Bex added.

"Which boy?" Mick asked. "How are we supposed to find him?"

That seemed like a very good question until I heard Liz beneath the roar of the sirens. "Well, it might be easier than you think."

She held out her hand, and for the first time I noticed that she wasn't wearing an ordinary watch. Instead, it was one of her custom designs. Tiny red dots on the screen shone like beacons in the dark. I thought back to our mission in the East Wing—the fingerprints, the DNA, and finally…Bex managed a triumphant grin. "We've got trackers."

Immediately we all turned and started outside, but stopped just as quickly. Steel covered every window—every door. The very security measures that were supposed to keep intruders out were keeping us in.

"We can't get out," Tina said, dismayed.

Hope seemed to fade. The dot on Liz's monitor—the signal from the trackers we'd planted in the boys' shoes weeks ago—grew farther and farther away. I thought of my mother's advice, and I knew that, more than ever, I had to be myself.

So I looked at my friends. "Yeah," I said slowly, "we can."

I told myself that I'd been training my whole life for something like this—that we weren't as helpless as I felt, and for the first time that night my heart stopped racing; I took a deep, cleansing breath. Liz handed me her watch, and I peered down at the dots. Mick went in search of CoveOps essentials. Five minutes later we were pushing through cobwebs, smelling the dusty air of my favorite passageway.

Our flashlights cut through the black, and in the distance the sirens sounded like a stereo someone had left on.

I know those shadowy spaces—I can walk them in the dark. Blindfolded. In high heels. But this time something else lay at the end of the tunnel.

As the corridor branched and twisted, carrying us away from the mansion, I looked down at the monitor on my wrist and saw that most of the dots lay between the mansion and town—exactly where the boys were supposed to be. But one solitary dot moved away, so that's the signal—the boy—we followed.

When we exited the tunnel I saw the deserted highway that stretched out in two directions. The flashing dot went farther and faster as we stood there, unable to catch up.

"What now?" Liz asked.

"Anna, run around the perimeter until you reach the guardhouse—get help!" In a flash she was gone.

"Bex," I said, turning to my best friend; but just then my words failed me as I heard screeching tires and saw headlights glowing. One of our vans drove fast in our direction then skidded to a stop. I breathed for the first time in what seemed like days, and relief washed over me. Help is here, I thought.

It was probably my mom.

Or Mr. Solomon.

But then the doors flew open. And I heard Macey yell, "Get in!"

"You stole a Gallagher Academy van," I said, kind of amazed.

Macey shrugged. "Commandeered, Cam," she said. "When I couldn't get into the mansion, and heard the Code Black sirens, I commandeered a van. And yes," she said, as if reading my mind, "that's something that troublemaking debutantes learn how to do before they go to spy school."

Our headlights cut through the black. Mist fell from the sky—a warm, damp reminder that we'd come a long way since winter.

As we drove through the darkness, I didn't feel the rush of adrenalin that usually comes with covert operations. Instead of excitement, I felt a creeping horror that there had been a double agent in our midst. So I didn't let myself think about the boy I'd almost allowed to kiss me; I didn't dare wonder if I'd ever let myself feel that way again.

I turned up the sound on the monitor on my wrist, listened as a soft beep, beep, beep filled the van, faster than before, and I knew we were getting close.

"Turn here," I instructed, and the highway disappeared. We crept over gravel and potholes. "Hit the lights," I said. The van inched along in the dark.

The beeping was faster now, steady. "This is it," said Bex.

The clouds parted; a sliver of moonlight fell onto an industrial complex. Massive metal buildings stood clumped together. Weeds battled with gravel and broken bits of asphalt for control of the ground.

"What is this place?" Macey asked.

"It's an abandoned manufacturing company," Liz explained. "But the school owns it now."

"It doesn't look like there's any security," Macey said.

And then every girl in the van said, "Look again."

Chain-link fence covered the perimeter. Probably a million dollars' worth of motion sensors lay imbedded in the ground. It was a fortress disguised as a ruin, and there wasn't a doubt in my mind that whoever we were following had come here for a reason.

"So we find whoever's in there and get the disc back?" Macey asked as if she isn't technically an eighth grader and two years away from Sublevel One.

"Yeah." I said.

"So I guess it's just like…" Bex started, but trailed off. "Just like last fall?"

On an academic level she was right. It was like our fall final. This was the same training ground, and we were still students, but as Mick started handing out comms units and Napotine patches, I couldn't help missing Mr. Solomon and his cryptic pep talks, the clear-cut missions that outlined the difference between pass and fail.

I couldn't stop thinking that things weren't academic anymore.

Chapter Twenty-six

It's amazing how things come back to you—how instinct and training can take hold.

In an instant Bex was disabling the van's tiny dome lamp so there would be no telltale spark when we opened the doors. Mick disabled the wires that charged the perimeter fence, and one by one we slipped beneath it, retreating into the distant corners of the complex, fading with the shadows and darkness and things that go bump in the night.

When you're approaching a subject in the dark, the thing you have to worry about most isn't being seen—it's being heard. And unfortunately, Liz was feeling chatty.

"Cam, I'm sure Zach's got a really good explanation. I just know he's not a bad guy." That was a nice sentiment—a hopeful thought—and I might have enjoyed it if Liz's foot hadn't been inches away from a nearly invisible trip wire that shimmered in the moonlight.

"Liz!" I hissed and leaped forward, pulling her to safety. "Why don't you wait here?"

"But …" she said, stumbling, sounding only slightly offended "…Teamwork is key to covert operations."

"I know," I whispered as softly as possible. "But I need someone to stand here and watch this corner," I said, relieved to see a great hiding place behind an old barrel full of rain. "Can you do that?" I asked. "Can you stay right here and tell me if anyone comes this way?"

Even in the dark I could see the relief that flooded Liz's face. She was going to observe. It was maybe the most scientific assignment I could have given her, so she retreated into the shadows and I walked on alone, past puddles that lay under the eaves of the metal roofs, dodging stray cats and piles of forgotten lumber.