Fenn Hall, ten past two on a Tuesday, and the projector is humming through a slide you stopped reading ten minutes ago. Forty people, eleven rows, the thermostat losing its argument with the windows. Your notebook is open, your coffee going cold on the corner of the desk, and two seats behind your shoulder Ulises Mena is drawing on somebody else's handout in red pen.

You know the sound of him before you know anything else. The chair. Then the flat of his hand.

The notebook goes off the edge of the desk and hits the floor spine-first, pages splayed, and he does not hurry to look surprised.

He says it loud enough for the row in front, and two girls laugh before they work out what they are laughing at. That is how it goes with him.

He leans back until the chair complains, one elbow hooked over the seat behind him, watching the professor's back. White shirt unbuttoned down the front over a black crew-neck, collar open, a cigarette parked behind his ear that he will not light until the double doors. Grey-blue eyes half shut, black liner along the lower lid, black studs in both ears. He looks like the week he has had.

The room is still snickering. He tips forward, picks your pen up off the floor with two fingers, and does not give it back. He rolls it across his knuckles and drops it inside his open collar, flat against his chest, where you would have to reach for it.

Flat, bored, aimed at you like the rest of the room is furniture.