He studied me like he was looking at a laboratory specimen. “While there are certainly other possible explanations for everything you’ve described, the number of events in that short a time is highly unlikely. You’ve had a headache, you say?”

I nodded, then regretted it as that intensified the ache. “Yes, ever since I woke up on New Year’s Day. At first I thought it was a hangover, but it wasn’t the typical hangover headache. I felt like my brain was too big for my skull. It’s not as bad now, but it’s a constant ache. And just now, when I walked through your doorway, that was the worst.”

“Hmm. Okay, I want you to try doing some magic.”

“Like what?”

“Think about something you want to make happen. Something simple and obvious that isn’t likely to happen on its own by coincidence.”

I looked around his cluttered office. There was very little in there that didn’t look like it was bound to topple over on its own at any moment. I finally pointed to the magnifying glass that lay on top of a pile of parchment on his desk. “I’m going to make that flip over.”

He nodded. “Okay, go for it.”

I concentrated, imagining the magnifying glass turning onto its side, and then falling over onto its other side. Slowly at first, and then more surely, it rose, turned over, and then landed again on the desk.

“Son of a bitch,” Owen said as he stared at the magnifying glass. It was the closest I’d ever heard him come to swearing in a language I recognized. Gloria probably didn’t approve of profanity.

“So it’s for real,” I said, just to confirm it.

“It’s real, all right. I felt the power, myself.”

“So, is this good or bad?”

“I don’t know. It depends on how and why it happened. The headache has me worried, though. That part’s not good, if it’s related.”

“How do we find out how and why it happened?”

“I don’t know that, either.” He shook his head, his forehead knit in a deep frown. “I’ve never heard of anyone spontaneously developing magical powers, especially not a magical immune. That should be absolutely impossible. If it is possible, then it changes everything we think we know about magical potential.”

“Well, obviously it’s possible because, well, hello!”

“Again, that comes back to how and why.” He knelt next to me, closed his eyes, and held his hands out toward me. Then he frowned even deeper and sat back on his heels. “That’s really odd.”

“A lot is really odd. Care to narrow it down?”

“You don’t feel like, well, you.”

“That would actually explain a lot about the past day or so, as well as what happened at the party, but wouldn’t I notice it if I’m not me?”

“As I told you earlier, every magical person has a sort of signature. You can learn to recognize magical people by the magic they emit once you get to know them and know their magic, even when they’re not actually using magic.”

“Like the magical equivalent of a signature perfume.”

“Exactly. But because you’re magically immune and have absolutely no magic in you, you’re magically blank. If I lost all my other senses, I’d still be able to find and recognize a familiar magical person. You would be mostly invisible to me.”

“Mostly?”

He turned red. “There are other things about you I’ve learned to recognize that aren’t in the realm of the usual physical senses. Anyway, you’ve got a magical signature right now, and it’s not the same as the slight hints of magic you get when we tinker with your immunity. I need you to do something else magical.”

I looked at the water glass on his desk and decided to fill it. As I concentrated on it, I felt the stirrings of power within me, and then the glass filled. I turned to look at Owen, who had an absolutely horrified expression on his face. “Oh, God, you’re Ari,” he said, backing away from me.

“I’m what? No, I’m Katie. I know I’ve been acting odd, but I’d know if I was someone else, wouldn’t I? I wouldn’t have been able to get through your office door. You have her specifically warded out, don’t you?”

He grabbed my wrist and stood up, tugging me with him. “Come on, we need to talk to the boss about this.” He pulled so hard, I had no choice but to go with him. My head nearly exploded again as I passed back through the doorway, but he barely gave me a chance to get my feet under me again before he took off, dragging me behind him. Jake moved as though to ask a question as we passed, but Owen ignored him and kept going. His grip on my wrist made me feel like I was a prisoner in custody, and I guessed that if he thought I had somehow been switched with Ari, I probably was.