I'm sitting on a train. The train is stopped at a station. I'm on the right-hand side and looking out of the window. Movement attracts my attention - a black girl is running across the footbridge which spans three platforms. She is struggling to get through as people who have alighted from my train are walking in the opposite direction to her. I wonder if she will catch the train. I speculate that she is possible on a final warning for lateness from her employer. Probably not. I root for her nevertheless. I wonder if I should stand in the doors so that she will catch the train. I decide not to. It's not my business. I don't know her. Why should I care? I still hope she gets on though. I'm in a good mood today. Sometimes I'm not and I think bad thoughts about humanity. I lose sight of her. Then I espy her enter the carriage. I'm pleased for her. She walks down the aisle. She is a little out of breath. She appears to be in her late twenties. Or early thirties. Her face is kind of thin and though not beautiful she is attractive - attractive-ish. She finds a seat next to a young guy and plonks herself down. The seat is facing the rear of the train and two rows away from mine. I am sitting in the direction of the travel. I prefer to be that way though I don't mind if I do have to sit the other way. I know that some people always have to be facing in the same direction as the train travels. A colleague of mine does.

The train pulls away and begins to accelerate. It is an electric train and electric trains can accelerate quickly. I turn my head and start to look at the scenery passing by.

I notice the guy sitting next to her is twisting round and talking to a young woman behind him. She has obviously just got on at the last station too. But I guess she got to the station in good time for the train. The guy and the girl continue with their conversation. I don't think they are anything other than acquaintances, but I wonder if either one or both are thinking of having sex with the other. I probably would. The woman that is. I'm not gay.

The black girl suddenly says to both of them, "Would you like me to swap seats? It'll be easier to chat then."

The girl says, "Thank you, that's most considerate of you."

The black girl gets out of her seat and they swap positions.

Kind and considerate. The black girl is kind and considerate. I like that. I warm to her though I have only known of her existence for minutes.

The next station is mine, so I get out of my seat and stand behind others in the aisle. To my right and sitting down is the black girl. She is fiddling with her mobile phone. Probably a boyfriend. I can't imagine she hasn't got a boyfriend.

The train slows to a halt and stops. The doors open and everybody begins to shuffle down the aisle. The black girl gets up. I say to her, "After you?"

She replies, "Thanks, it's amazing how many people you can get in just two coaches."

Her voice is well spoken now that I can hear her clearly. Almost 'cut glass'. That surprises me – it’s a working-class town.

"It is, isn’t it," I respond, and nearly lost for words.

She walks in front of me and steps onto the platform. She exits the station, and she goes left whilst I turn right and walk to the road bridge that crosses the line. I glance momentarily in her direction and see that she is talking and walking to an older white guy. I wonder what she does for a living. I wonder if I will ever see her again. I wonder what it would be like to fuck her. I wonder if she is kinky.

I remember that I am happily married...