Petra pulled out her screen, began snapping pictures.

“It’s kind of like a rune,” Theo said. “Or at least the ones I’ve seen in The Revenge of Freja.”

“Such a great flick,” Hugo said. “And yeah, they do look similar.”

“Phenomenal flick,” Theo said.

“It doesn’t feel like magic,” I said.

“It was spelled to be neutral,” Hugo explained. “Designed so it doesn’t emit any magic as it does its thing.”

“So Sups can’t sniff out the Cornerstones and manipulate them.”

“That’s the theory,” Hugo agreed. He leaned forward, brushed away an invisible bit of dirt from the stone with obvious care and attention.

“The Cornerstones may be neutral,” I said, “but I don’t think the wards are. I think that’s how Rose figured out where the South Gate and the machine were.”

“Do you know what the symbols say?” Theo asked. “Or how the magic works?”

“No. They didn’t give us any of that information, at least as far as I was aware. Only how to clean and oil the machine. I had a schedule to follow, and I’ve only missed it twice. I broke my collarbone a few years ago, and it was a couple of weeks before I could really get in there. One year I had pneumonia, and I was down for nearly a month.”

Those both sounded like normal human things. Not demon interference or manipulation.

“Did anyone ever fill in for you?” I asked.

Hugo’s eyes widened with surprise. “Well, no. I couldn’t tell anyone else, so they couldn’t, like, show up and do it.”

Theo caught on to my line of questions and where I was going with them. “Did anyone ever ask you about it? I mean, people asked about your job, right? Just in casual conversation, and you told them—what—that you worked on a machine?”

“Well, kind of. Folks I game with have known me forever.” He blushed a little. “But I didn’t give them any details. I make a little extra money streaming my games on the side. Some just assume that’s my real job.”

“Anyone ever follow you here? Or have you seen anyone suspicious hanging around?”

“No,” he said with a laugh, but his expression sobered. “You think someone caught on, or maybe she had someone follow me or become friends to find out where the Cornerstone was? But how would she find me in the first place?”

“Just eliminating possibilities.” I looked at Hugo. “What’s the machine’s range?”

“What?”

“I think she’s asking how close the demon has to be for the machine to trigger,” Petra said, and I nodded.

“Oh, well, I don’t know.” Hugo ran a hand over his hair. “Anywhere within its perimeter, I guess.”

“Which is?” Petra asked.

He winced. “I don’t know that, either. I’m sorry. I’ve never seen it work before. I just know it was supposed to target the demon if she got close.”

I didn’t detect any magic in his lack of knowledge. If Petra was right, and some kind of memory spell affected Patience’s ability to remember or talk about the wards, it hadn’t affected him. Maybe because he hadn’t been alive at the time.