No, he mustn't think about it, or indeed about anything, and especially not about heroin, because heroin was the one thing that really worked, the only thing that stopped him scampering around in a hamster's wheel of unanswerable questions. Heroin was the cavalry. Heroin was the missing chair leg, made with such precision that it matched every splinter of the break. Heroin landed purring at the base of his skull, and wrapped itself darkly around his nervous system, like a black cat curling up on its favourite cushion. It was as soft and rich as the throat of a wood pigeon, or the splash of sealing wax onto a page, or a handful of gems slipping from palm to palm.