“I’m not sure I follow.”

“Think it through again.” Mike leaned forward suddenly, his eyes burning with excitement born of an epiphany. “We know from Paulus’ diary”–he jabbed his forefinger at a thin leather journal, one of many such volumes strewn haphazardly across the desk—”that he had the book when he rode into town.” A thrust of his leg sent the wheeled chair on which he sat rolling noisily across the hardwood floor to collide with a large metal filing cabinet. Mike pulled a folder from atop the filing cabinet, sending random papers fluttering through the air like wind-tossed leaves. “And we know from this report that when the Sons of Horus caught him trying to sneak out on the South Shore Line, the Manuscript wasn’t on him. He ditched it somewhere before trying to leave.”

“So? He passed it off to somebody else. Or sold it.”

“Come on. Who’s he going to trust with it? Its misuse was why he stole it in the first place.”

“But if he hid it somewhere in town, why is there zero trace of it? The Sons aren’t stupid. That thing packs an aura like… I don’t know. I mean, we could feel it all the way out in Des Moines. No way Paulus could hide that.”

Mike was tapping his fingers on the desk, impatience writ clear across all his features. “You’re not thinking. OK, so no geas can hide the Manuscript. But nobody can see it, so obviously something’s hiding it. Something else right here in the city.” He was channeling the condescending teacher now; he was going to reel me along until I stumbled upon the destination he’d clearly already reached. When I didn’t reply immediately, he dropped the subtlety another notch. “What is there, in the city of Chicago, that is powerful enough to smother the aura of the third-most-potent magical tome on the continent?”

I was slow, but I was trying. “Something to smother an aura—not a spell, which’d leave an even bigger footprint than the object it hid.” Mike nodded, and I felt a surge of schoolboy pride. The last piece clicked into place, and I blurted excitedly: “Manhattan.” Mike nearly squawked with glee. “Fermi. The nuclear reaction.”

“Yes! The birth of the modern world. It’s a magical dead zone. When the reaction went off, it must’ve blown a hole in the ley-line grid big enough to drive a blimp through.”

“Or hide the Preter Manuscript.” I was grinning like an idiot.

“Exactly. The Sons were looking for an aura spike, not a gap. And get this: Stagg Field is long gone, but guess what’s sitting right where it used to be?”

I knew this one. “A library. The University of Chicago.”

Mike nodded. “We need to get there fast. If we can figure it out, so can the Sons. Persephone still owes you from the whole Hellfire Club business, right? Think she can conjure us up some faculty IDs in the next half-hour?”

She certainly wouldn’t appreciate being invoked at this hour, but she did owe me. “No problem.”

“Then pack your bags and your library card. We’ve got a book to check out.”

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