They call it "The Asylum Line" down towards Upton Park, because of the number of asylum seekers (or, more accurately, people who might be superficially taken for asylum seekers) who live on that stretch of the network. I don't see them, and in fact they're something of a myth. The East End has experienced an influx of immigration over the last five years but it has come from the democracies of the Baltic states, rather than from wild despotic outposts further afield. The people who have sat opposite me this week have been as unexotic as a sandy-haired Polish carpenter. Less exotic, in truth, as they have, in the main, been native English speakers. I'm disappointed. There has also been a dearth of really hot girls for me to describe in minute, discomfiting detail (I'm doubly disappointed) but that's largely a function of this exercise. My self-imposed rules insist that I can't choose who sits opposite me. And under normal circumstances, I'd sit opposite the hot girl, if there is one available. I'm happily married, and not on the prowl for any kind of extra-mural shenanigans, but given the choice I'd always sit opposite the hot girl. I consider it an aesthetic duty to do so, but of course I'll always give up that seat to the elderly, infirm or pregnant, because basic morality trumps aesthetic duty.

Only just.

There's a grey area, of course - women who might simply be fat in an odd way, or consider themselves in "late middle age" - and my technique here, generally, is to stand and look away from the person to whom I wish to bequeath my seat. It's up to them. Opportunists will occasionally sneak into the seat before the borderline decrepit/knocked up/fat in an odd way woman can get to it. But that's on their conscience, the opportunist that is, not mine.

The train this morning is empty. It's Friday, early August. People go in late on Fridays and half of London is on holiday. The seat opposite me remains vacant, like a non-specific accusation until Blackfriars.

BLACKFRIARS - VICTORIA

White male, 45-60 yrs, short-sleeved shirt, no tie, (does anyone wear a tie anymore?) and rather daring trousers. Or rather trousers from a rather daring suit. Daring is a relative term. He is sit-com dad and the suit is a bold check, but still blue on blue. They aren't clown trousers or anything. He's a big fellow, his hair is greying in a dynamic, non-emasculating way. He has a Grande coffee and a twinkle in his eye. He is another anonymous businessman, but I like him. He shuffles sideways to accommodate...

VICTORIA - SOUTH KENSINGTON

White female, 25 - 40 yrs, Slavic, possibly Baltic, kinked hair (I'm sure there's a proper name for it) weird cowgirl get-up, boots and clothing with senseless embroidery, long bony fingers and eye shadow in the nastiest shade of pink imaginable. East European cowgirls. This is London.