I shrugged. “The explosion came from inside the pentagram’s center, but not necessarily from the pentagram. I mean, it could have been a normal device of some kind.”

“Square in the middle of the giant, scary pentagram?” Murphy asked.

“Maybe,” I said, nodding. “It depends on what the pentagram was being employed for. And to know that, I’d have to know which way was its north.” I circled the topmost point of the chalk pentacle. “The direction of the first line, I mean.”

“Does it make a difference?”

“Yeah,” I said. “Most everybody draws those stars just like I did. Bottom left to the topmost point as the first stroke. That’s how you draw it when you want to defend something, ward something away from a location, or banish a spiritual entity.”

“So this could have been a banishing spell?” Murphy asked.

“It’s possible. But you can do a lot of other things with it, if you draw it differently.”

“Like build a cage for things,” Murphy said.

“Yeah.” I frowned, troubled. “Or open a doorway for something.”

“Which, judging by your face, would be bad.”

“I…” I shook my head. I didn’t even want to know what kind of terror would need a pentagram that huge in order to squeeze into our world. “I think if something sized to fit this pentagram had come through it, there would probably be more than one building on fire.”

“Oh,” Murphy said quietly.

“Look, until I know what the pentagram’s purpose was, all I can do is speculate. And there’s something else weird here, too.”

“What’s that?”

“There’s not a trace of residual magic, and there should be. Hell, with this much power being tossed around, the whole area should practically be glowing. It isn’t.”

Murphy nodded slowly. “You’re saying they wiped their prints.”

I grimaced. “Exactly, and I have no idea how to do it. Hell’s bells, I didn’t know it was possible.”