His first thought is Lasciel. That's probably not unreasonable. She does have a habit of showing up when his brain is otherwise occupied and spinning crazy illusions, though she usually does it when he has some sort of crisis happening. Until now, there was no crisis. He takes a moment to snarl a warning at her inside her mind, just in case it is Lasciel, though there's a distinct lack of leggy busty blondes in Greek tunics immediately apparent.

What is apparent, though, is a girl, surely not much older than Molly, wandering unconcernedly across the room, her hands glowing. Harry reaches for his amulet with his right hand, the clumsy, gloved left hand resting on Mouse's head. The dog's snarls subside a little; apparently it's not the girl he's snarling at, but their surroundings.

Does that mean this is real, that Mouse can see it and felt what just happened?

Harry's face is screwed up in concentration, watching the girl. There's no sense of power in what she's doing, at least not magical power.

Harry holds out his silver amulet, power running through it to make it glow.

"I know how to make an entrance," he says. "Walk on in and boom, instant darkness."

Just like magic.