Unimaginable, really, that less than two months from now one of his colleagues from abroad, a woman with delicate, birdlike features, will appear at the door to my office and identify herself as a friend of Bob’s. When she asks, I take her down the hall to the room with the long table and then to his empty office. I do this without saying anything, because there’s nothing to say, and she takes it all in with small, serious nods until the moment she sees his blackboard covered with scribbles and arrows and equations. At that point her face loosens and she starts to cry in long ragged sobs. An hour later I go back and the office is empty. When I erase the blackboard finally, I can see where she laid her hands carefully, where the numbers are ghostly and blurred.

She’s always been older than me.”

I imagine it as a place of stillness, where the particles of dust stop spinning and hang motionless in deep space.