"It is possible, of course," he said, "to imprison someone within the pattern of a carpet for a thousand years or so. That is a particularly horrible fate which I always reserve for people who have offended me deeply - as have these magicians! The endless repetition of colour and pattern - not to mention the irritation of the dust and the humiliation of stains - never fails to render the prisoner completely mad! The prisoner always emerges from the carpet determined to wreak revenge upon all the world and then the magicians and heroes of that Age must join together to kill him or, more usually, imprison him a second time for yet more thousands of years in some even more ghastly prison. And so he goes on growing in madness and evil as the millennia pass. Yes, carpets! Perhaps ..."