"You mean stolen artifacts?"

"What did I just say? He probably has some kind of arrangement with security there. Maybe he stashed it in a staff locker or something."

I parked in front of the Field Museum under a no parking sign. There were a couple of actual spots I could have used, but the drive was even closer. Besides, I found it aesthetically satisfying to defy municipal code.

I put the Beetle's parking brake on and got out into the rain. "Stay, Mouse," I said. "Come on, Butters. Can that thing get us close to the book?"

"Within ten feet or so," he said. "But Harry, the museum is closed. How are we going to—"

I blew out the glass of the front door with my staff, just as I had at Radio Shack.

"Oh," he said. "Right."

I strode into the main hall, Butters walking on my heels. Lightning flashed, abruptly illuminating Sue the Tyrannosaurus in all her bony Jurassic glory. Butters hadn't been expecting it, and let out a strangled little cry.

Thunder rolled and I got out my amulet for light, lifting an eyebrow at Butters.

"Sorry," he said. "I, uh… I'm a little nervous."

"Don't worry about it," I told him, my own heart pounding wildly. The sudden reveal of that monstrous skeleton had shaken me, too.

Don't look at me like that. It was a tense sort of evening.

I looked slowly around the place, and Listened for a moment. I couldn't sense anyone's presence. I opened my Sight again, just for a quick glance around, but I didn't see anyone hiding behind a veil of magic. I backed off. "Check again."

He did so, though the shining floor of the museum didn't take the chalk as readily as concrete. A few minutes later he nodded toward Sue and said, "Over that way."

He broke the circle and we hurried across the enormous floor. "Try to keep quiet," I told him. "Security might still be around."

We stopped at Sue's feet and checked again. Butters frowned, peering around. "This can't be right," he said. "According to the GPS, these coordinates are inside that wall. Could Bony Tony have hidden it in the wall?"

"It's stone," I said. "And I think someone might have noticed if he'd torn out a wall in the entry hall and replaced it."

He shook the GPS a little. "I don't get it, then."

I chewed on my lip and looked up at Sue.

"Elevation," I said.

"What?"

"Come on." I pointed up. "There's a gallery overlooking the main hall. It must be either up there or on a floor below us."

"How do we know which?"

"We look. Starting with the upstairs. The levels below us are like some kind of gerbil maze from hell." I started for the stairs, and Butters came after me. Going up them was a pain, but my instincts were screaming that I was right, and my excitement made the discomfort unremarkable.