"During my time at Eton, I led regular nighttime adventures, and word spread. I even thought about charging to take people on trips. I remember one where we tried to cross the whole town of Eton in the old sewers. I had found an old grill under a bridge that led into these four-foot-high old brick pipes, running under the streets. It took a little nerve to probe into these in the pitch black with no idea where the hell they were leading you; and they stank. I took a pack of playing cards and a flashlight, and I would jam cards into the brickwork every ten paces to mark my way. Eventually I found a manhole cover that lifted up, and it brought us out in the little lane right outside the headmaster's private house. I loved that. "All crap flows from here," I remember us joking at that time."