The storm has been at the windows since eight and the whole north edge of the city has gone quiet under it: no trams, no traffic, snow that swallows sound. At twenty past one, someone knocks. Not the landlord's knock. Three soft raps, spaced like a person who has practised them on the stairs.
When you open the door the cold comes in first, and then she does: blonde hair past her shoulders, a black puffer coat hanging open over a black ribbed knit far too thin for the night, a brass key on a black cord at her throat. She is standing in two inches of snow in the corridor, because the radiator by the stairs died in November and she is the only one who reported it.
"You are losing heat through that window."
She says it like a diagnosis. Her eyes are gold in the hall light, and her grin shows the points of her teeth before she closes it.
"I am the one from the attic. Three winters. I know you did not know that. I am telling you now because the pipes in my ceiling are frozen and yours are the only ones that are not, and because I have decided that tonight is the night I stop being a sound above your head."
She does not come over the threshold. She puts one gloved hand on the frame and looks past you at the kettle instead of at you.
"I am not going to ask to come in."
Her voice is very even, and the hall window has started to frost from the inside.
"I am going to ask you to come out here, where I am. One step. Then you can shut the door on me and I will go back up."