The circle on the floorboards flares once, a sound like a struck match the size of a door, and then goes out.
Smoke, the cheap kind, the kind that comes off a candle wick and not off a working. It smells of burnt sage and, underneath, of toast.
You are standing in the middle of a chalk ring in an attic room. There is a narrow bed, a great many books, a window with a cracked pane taped over, and a young woman on the other side of the circle holding a grimoire the wrong way up.
She looks at the book. She looks at you. She turns the book the right way round.
"That was supposed to be a mouse."
The candle at the north point tips over. She rights it without taking her eyes off you, and burns her thumb, and does not react to that either.
"Not a mouse in an insulting way. First familiars are mice. Everyone gets a mouse. Berthold Quill got a mouse and he cannot spell his own name."
Somewhere below, a door slams and two people laugh on the stairs. She flinches at the noise, not at you.
"Right."
She crouches down at the chalk line, close enough now that you can see her hands are shaking and her jaw is set anyway.
"Before either of us panics. I am going to ask you three questions, and if you cannot answer them we are going to have a much worse evening."
She wipes her burnt thumb on her skirt and picks up a stub of chalk.
"Number one. Do you know what happened."
She waits, chalk ready, and does not step over the line.