I was also armed with a pretty good dose of skepticism at their motives. I assumed the brat pack was leading me into trouble, that the “treasure” at the end of our hunt was a prank with my name on it. Given the strong possibility that I’d have to make a run for it, I was glad I’d worn boots. I figured they offered at least a little more traction than the flip- flops, and they’d probably pack a bigger wallop, if it came to that.

Scout was still gone when we left the suite, three brat packers and one hanger- on, Veronica in the lead. It was nearly ten p.m., and the hallways were silent and empty as we followed the same route I’d taken behind Scout two days ago—down the stairs to the first floor, back through the long, main corridor to the Great Hall, then through the Great Hall and into the main building. But instead of stopping at the door Scout had taken, we took a left into the administrative corridor I’d taken with M.K. earlier in the day.

We hadn’t yet turned on our flashlights, so I’m not entirely sure why we had them. But when footsteps suddenly echoed through the hall, I was glad we hadn’t turned them on. Veronica held out a hand, and we all stopped behind her. She turned, excitement in her eyes, and motioned us back with a hand. We tiptoed back a few steps, then crowded into one of the semicircular alcoves in the hallway. I gnawed my lip as I tried to control my breathing, sure that the thundering beat of my heart was echoing through the hallway for all to hear.

After what felt like an hour, the sound of footfalls faded as the person—probably one of the clipboard-bearing dragon ladies—moved off in the other direction.

Veronica peeked out of the nook, one hand behind her to hold us back while she surveyed the path.

“Okay,” she finally whispered, and we set off again—Veronica, then Mary Katherine, Amie, and I. I couldn’t help but glance behind us as we moved, but the hall was empty except for the cavernous silence we left in our wake, and the moonlight-dappled limestone floor.

We continued down the administrative hallway, but before we got as far as Foley’s office, we turned down a side corridor that dead-ended in a set of limestone stairs. The air got colder as we descended to the basement, which didn’t help the feeling that we were heading toward something unpleasant. We probably were headed toward the nasty that had been chasing Scout, but I couldn’t imagine the brat pack had any clue what lurked in the corridors beneath their fancy school. If they had known, they surely would have tortured Scout about it. They seemed like the type.

“Almost there,” Veronica whispered as we reached the bottom of the staircase. True to St. Sophia’s form, we entered another limestone hallway. I’d heard about buildings that contained secret catacombs, but I wondered why the nuns had bothered building out the labyrinthine basement of the convent—a task they’d taken on without trucks, cranes, or forklifts.

“Here we are,” Veronica finally said as we stopped before a simple, wooden door. The word CUSTODIAN was written in gold capitals across it, just like the letters on Foley’s office.

I arched an eyebrow at the door. “We’re going into the janitorial closet?”

Without bothering to answer, Mary Katherine and Veronica fiddled with the brass doorknob, then opened the door with a click.

“Check it,” Veronica said, grinning as she held the door open.

I walked inside, and my jaw dropped at the scene before me.

The room was a giant limestone vault, completely empty but for one thing—it held an entire, little Chicago, a scale model of the city. From a two-foot-high Sears Tower and its two gleaming points (which even I could recognize), to the Chicago River, to the Ferris wheel at Navy Pier. All in miniature, all exactingly detailed, laid out across the floor of the giant room by someone who clearly loved Chicago—someone who knew Chicago.

“Who did this?” I asked.

“No clue,” Veronica said. “It’s been here as long as we’ve been here. Pretty sweet, huh?”

“Very,” I muttered, eyes wide as I walked the empty perimeter of the limestone room, just taking it all in.

The model was almost totally devoid of color—the buildings and landscape rendered in various shades of thin, gray cardboard—but for symbols that were stamped on a few points across the city. In navy blue was a symbol that looked like four circles stuck together, or a really curvy plus sign. In apple green was a circle enclosing a capital Y.

Markers, I thought, pointing out the locations of two kinds of something across the city.

I moved into the middle of Lake Michigan—an empty space across the floor—and peered between the buildings, looking for St. Sophia’s. When I found East Erie, I realized there were two symbols nearby: the four-circle thing on Michigan Avenue and, more interesting, the enclosed Y only a couple of blocks from St. Sophia’s. “What do the symbols mean?” I asked.

I got only silence in response.

I glanced up and looked behind me just in time to watch them shut the door, and just in time to hear the lock tumblers click into place. I hurdled Navy Pier, ran to the door, gripped the doorknob in both hands, and pulled.

Nothing.

I shook it, tried to turn it, pulled again.

Still nothing, not even a knob to unlock the door from the inside. Just a brass keyhole.

“Hello?” I yelled, then beat my fist against the door. “Veronica? Amie? Mary Katherine? I’m still in here!”

I added that last part in the off chance they were somehow unaware that they’d locked me into a room in the basement of the school; in case they’d forgotten that the four of us had traveled the halls of St. Sophia’s to get to this underground room, but only three were headed back up.

But it wasn’t an accident, of course, and the only answer I got back was giggling, which I could hear echoing down the hallway.

“Way mature!” I yelled out, then muttered a curse, mostly at my own stupidity.

Of course there was no candy, no Tab, no hidden cigarettes, or black-market energy drinks down here. There was a treasure—the brat pack had stumbled upon something, a hidden room that contained an intricate scale model of the city. But they’d probably missed the point, being only interested in how to use the room to prank me—how to punk me.

I kicked a foot against the door, which did nothing but vibrate pain up through my foot. Turned out, even my favorite boots didn’t provide much more insulation than flip- flops. I braced one arm against the door and rubbed my foot with my free hand, berating myself for following them into the room.

Traipsing around the school was one thing; I’d done that already. But being locked in a custodial closet in the all-but-abandoned basement of a private school was something else. My love of exploration notwithstanding, I knew better.

When my foot finally stopped throbbing, I stood up again. For better or worse, I was stuck down here, in a hidden room that was probably a little too close to whatever lurked behind the metal door. It was time for action.

One hand around my pink flashlight, the other on my hip, I took a look around. Unfortunately, the obvious exit wasn’t an option. The door was locked from the outside, and I didn’t have a key.

“Hold that thought,” I muttered, put my flashlight on the floor. This was an old building, and I had a skeleton key. I pulled the ribboned room key off my head.

“Come on, Irene,” I said. Two fingers crossed for good luck, I slipped the key into the lock.

The tumblers didn’t budge.

I muttered out another curse, then pulled back the key and slipped the ribbon over my head again. I slid my gaze to the flashlight on the floor and considered, for a minute, pummeling the lock with it, but God only knew how long I’d be down here. Sacrificing the flashlight probably wasn’t the brightest idea (ha!).

I stepped back and surveyed the door. Like the doors in the main building, this one was an old-fashioned panel of thin wood, attached to the jamb by two brass hinges. The pins in the hinges were pretty big, so I figured I could try to pull them out, unhinge the door, and squeeze through the crack, but I really didn’t like the thought of ending up in Foley’s office again, this time for destruction of St. Sophia’s property. There was no doubt the brat pack would tell her who was responsible, and I guessed that was the kind of thing she’d put in my permanent record.

All that in mind, I put “taking the door apart” at the bottom of my mental list and glanced back at the rest of the room, looking for another way. What about a secret door? Since Foley had one, it didn’t seem far- fetched that I’d find one in a secret, locked basement room. I walked the perimeter of the room, pressing my palms against the limestone tiles as I walked, hoping to find some kind of trigger mechanism.

I made two passes.

I found nothing.

Just as I was about to give up on an escape route that didn’t involve dismantling the door, something occurred to me. The model had obviously taken a lot of work, a lot of craftsmanship, with all those tiny buildings, all that architecture. And that meant someone spent a lot of time in here. A lot of hours in here.

But the door was locked from the outside, so what if the architects got locked in while they were whiling away the hours on their obsessively detailed project? Wouldn’t they need another way out? Surely they—or he or she or whoever—had their own escape route. I must have missed something.

I was on the far side of the room when I saw it—when I noticed the glint of light, the reflection, on the eastern edge of the city. I cocked my head at it, realizing the glint was coming from the two spires on the Sears Tower.

I moved closer.

The spires were metal, which was weird because they were the only metal in the tiny city. Everything else was rendered in that same, gray paperboard.

“Interesting,” I mumbled, and kneeled down in what I assumed was a branch of the Chicago River. I reached out and carefully, oh so carefully, tugged at a spire.

It didn’t budge.

“Come on,” I said, and reached for the second. I grasped the end, wiggled, and felt it begin to slide free of the cardboard. One tug, then another, just enough to pull the metal through, but not hard enough to tear the roof from the building.

It finally slid free. I held it up to the light.

It was a key.

“Oh, rock on,” I said with a grin, then rose from the lake. It may not have been a huge victory—and I wasn’t even sure the key would work in the lock—but it sure felt like one. A victory for the architect who’d been locked in, and a victory for me. And more important, a loss for the brat pack.

I walked along the river until I reached the lake, then turned for the door, where I slipped the key into the lock and turned.

The lock flipped open.

I’m not embarrassed to say that I did a little dance of happiness, yellow boots and all.

Thinking the next person who was locked into the room might need the key, I pulled it from the lock and returned it to its home in the Sears Tower. I glanced across the city, making a mental note to tell Scout about the model in case she hadn’t already seen it. I had a suspicion the symbols on the buildings were related to whatever she was doing, and whatever “litter” she and her friends were battling against.

And speaking of battling, it was time to consider my next step.

Option one involved my returning to the suite to face down Veronica et al. They’d gloat about locking me in; I’d gloat about getting out. Not exactly my idea of a thrilling Thursday night.

Option two was a little riskier. I’d joined the brat pack in their trip to the basement on the off chance they might lead me somewhere interesting. Success on that one, I think.

Now that they’d returned to the Kingdom of Pink, I had the chance to do a little exploring of my own. So, for the second time in a single night, I opted for danger. I’d managed to finagle my way out of a locked room, so I figured luck was on my side.

I took a final look at the city and pulled the door closed behind me.

“Good night, Chicago,” I whispered.

Maybe not surprising, the hallway was empty when I emerged from the custodian’s closet, the brat pack nowhere to be seen. They were probably celebrating their victory somewhere. Little did they know. . . .

The corridor split into two branches—one that led back to the stairs and the first floor, and one that probably led deeper into the basement. My decision to play Nancy Drew already made, I took the road not yet traveled.

I moved slowly, one shoulder nearly against the wall, trying to make myself as invisible as possible. The hallway dead-ended in a T-shaped corridor; I headed for it. This part of the basement was well lit, so I kept the flashlight off, but gripped it with such force, my palm was actually sweating. I was still in the basement, still close to whatever nasties Scout had locked behind the big metal door. That meant I needed to be on my guard.

I made it to the dead end without incident, then glanced down the left- and right-hand corridors. Both were empty, and I had no clue where I was relative to the rest of the building. Worse, both hallways were long and dark. There were no overhead lights and no wall sconces—just darkness.

Not the best of choices. I didn’t have a coin to flip or a Magic 8-Ball to ask, so I went with the only other respectable method of making a decision as important at this one.

Unfortunately, I’d only made it through “eeny meeny miney mo” when the ground began to rumble beneath my feet. I was thrown forward into the crux of the hallway, and had to brace myself against the limestone wall to stay upright as the floor vibrated beneath me.

But just as suddenly as it had begun, the rumbling stopped. My palm still flat against the limestone bricks, heart pounding in my chest, I looked up at the ceiling above me as I waited for screaming and footfalls and other telltale signs of the aftermath of the Earthquake That Ate Chicago.

There was only silence.

I snapped my gaze to the left as hurried footsteps echoed toward me from that end of the hallway and tried to swallow down the panic.

I flicked on my flashlight and swung the beam into the dark, the arc of light barely penetrating the blackness, even as I squinted to get a better look.

And then I saw them—Scout and Jason behind her, both in uniform, both running toward me as if they were running for their lives. I dropped the beam of the flashlight to the floor to keep from blinding them, afraid that’s exactly what was happening.

“Scout?” I called out, but fear had frozen my throat. I tried again, and this time managed some sound. “Scout!”

They were still far away—the corridor was a deep one—but they were running at sprinter speed . . . and there was something behind them.

It almost didn’t surprise me to see that they were being chased. After all, I’d already helped Scout try to escape from something. But I’m not sure what I expected to see chasing her.

As they drew closer, I realized that behind them was the blonde we’d seen outside the pillar garden on Monday—the girl with the hoodie who had watched us from the street. She ran full-bore behind Scout and Jason. But even as she sprinted through the corridor, her expression was somehow vacant, a strange gleam in her eyes the only real sign of life. Her hair was long and wavy, and it flew out behind her as she ran, arms pumping, toward us.

Suddenly she pulled back her hand, then shot if forward, as if to throw something at the two of them. The air and ground rumbled, and this time, the rumble was strong enough to knock me off my feet. I hit the ground on my knees, palms extended.

By the time I glanced up again, Scout and Jason were only feet in front of me. That meant the blond girl was only a few yards behind. I saw the look of horror on Scout’s face. “Get up, Lily!” she implored. “Run!”

I muttered a curse that would have made a string of sailors blush, and ignoring the bruises blossoming on my knees, jumped to my feet and did as I was ordered. The three of us took off down the hallway, presumably for a safer place.

We ran through one corridor, then another, then another, heading in the opposite direction of the path I’d taken with the brat pack—probably a good thing, since there was no giant metal door in that part of the convent to keep them out.

To keep her out.

Whatever juju the blonde used before, she used again, the ground rumbling beneath our feet. I don’t know how she managed it, how she managed to make the earth—and all the limestone above it—move, but she did it sure enough. We all stumbled, but Scout reached out a hand and grabbed at the wall to keep her balance, and Jason caught Scout’s elbow. I caught limestone, the stones rushing toward my face as she knocked me off my feet again. I braced myself on my hands, the pads of my hands burning as I hit the floor.

They were on their feet again and yards ahead before they realized I wasn’t with them.

“Lily!” Scout screamed, but I was already looking behind me, watching the blonde. The earthquake- maker just stood there, and I figured if I was already on the floor, there wasn’t much else she could do to me.

Of course, that didn’t mean the guy who stepped out from behind her couldn’t do damage. He was older than she was—college, maybe. Curly dark hair, broad shoulders, and blue eyes that gleamed with a creepy intensity. With a hunger. And all that hunger and intensity was directed at me.

I swallowed down fear and panic and tried to make my brain work, tried to make my arms and legs push me up from the floor, but I was suddenly puppy-clumsy, unable to order my limbs to function.

The boy stepped beside the blonde, muttered something, and just as she had done, whipped his hand in my direction.

The air pressure in the room changed, and something flew my way, some thing he’d created with that flick of his hand. It looked like a contact lens of hazy, green smoke, but it wasn’t really smoke. It wasn’t really a thing. It was more like the very air in the room had warped.

Still on the floor—only a second or two having passed since I fell to the ground, time slowing in the midst of my panic—I stared, eyes wide, mouth open in shock as it moved toward me. Nothing in my life in Sagamore, or my week in Chicago, had prepared me for . . . whatever it was. And whatever it was, it was about to make contact.

They say there are moments in your life when time slows down, when you can see your fate rushing toward you. This was one of those times. I had a second to react, which wasn’t enough time to move out of the way, so I turned my back on it. That warp of air slammed into me with the force of a freight train, pushing the air from my lungs. It arced across my body like alien fire, like a living thing that tunneled into my spine, through my torso, across my limbs.

“Lily!” Scout screamed.

The floor rumbled beneath me again, and I heard a growl, a roar, like the scream of an angry animal. I heard shuffling, the sounds of fighting, but I could do nothing but lie there, my body spasming as pain and fire and heat raced through my limbs. I blinked at the colors that danced before my eyes, the world—or the portions of the floor and room that I could see from my sprawled-out position on the floor—covered by a green haze.

I must have passed out, because when I lifted my eyelids again, I was in the air, cradled by strong arms. I looked up and found bright eyes, eyes the same blue as a spring prairie sky, staring back at me.

“Jason?” I asked, my voice sounding hollow and distant.

“Hold on, Lily,” he said. “We’re going to get you out of here.”

The world went black.