1

I can at least be sure of her name. It was Maria Kovalenko, Masha to her friends. She was standing on the station platform at Ploshchad Revolyutsii, Revolution Square, when I first caught sight of her. I could see her face for about five seconds before she took out a little makeup mirror and held it in front of her. With her other hand she put on a pair of sunglasses that I remember thinking she might have just bought from a kiosk in an underpass somewhere. She was leaning against a pillar, up at the end of the platform where the civilian statues are--athletes, engineers, bosomy female farmhands, and mothers holding muscular babies. I looked at her for longer than I should have.

There's a moment at Ploshchad Revolyutsii, a visual effect that happens when you're transferring to the green line from that platform with the statues. You find yourself crossing the Metro tracks on a little elevated walkway, and on one side you can see a flotilla of disc-shaped chandeliers, stretching along the platform and away into the darkness that the trains come out of. On the other side you see other people making the same journey, only on a parallel walkway, close but separate. When I looked to the right that day I saw the girl with the sunglasses heading the same way.

I got on the train for the one-stop ride to Pushkinskaya. I stood beneath the yellow panelling and the ancient strip lighting that made me feel, every time I took the Metro, as if I was an extra in some paranoid Donald Sutherland film from the seventies. At Pushkinskaya I went up the escalator with its phallic lamps, held open the heavy glass Metro doors for the person behind me like I always used to, and made my way into the maze of low-slung under...