He boarded the bus on Hampstead High Street. The dye job partially covering his grey roots showed he had once cared about his appearance. His pastel yellow acrylic jumper and regular-bloke glasses suggested he had - recently - been a decent member of the community. But now the front of his jumper was a mess of unidentifiable smears, and the back had four large blood stains - not quite red, not yet brown - in a horizontal line, as though he had been stabbed repeatedly in the kidneys. He clung on to a half-full bottle of white Martini as he ricocheted down the bus, and sat down heavily next to me. "Piss off cunt," he said, quite clearly. I did.