INSIDE the gatehouse, a bicycle is leaning against the wooden portcullis. Yo-yo grabs it and climbs aboard. It's a Penny Farthing. Hell's bells. He struggles to keep it under control and wobbles through the door towards the Minster. Over his shoulder he sees Mister Vanilla seize a small, child's (or a small child's) bike and set off in pursuit. They cycle past the rooftops of High Petergate, the boy on the Penny Farthing, the hugely fat man on the little kid's bike, the saddle sandwiched between his vast buttocks thusly-