Plato, the orator, summons the citizens of London on ritual occasions to impart the ancient history of their city. He dwells particularly on the unhappy era of Mouldwarp (AD 1500-2300), which existed before the dimming of the stars and the burning of the machines. He lecturesupon THE ORGIN OF SPECIES by the nineteenth-century novelist Charles Dickens and upon the pantomimic routines of Sigmund Freud. But then he has a dream, or vision, or he goes on a real journey - opinions are divided - and enters a vast underground cavern, where citizens of Mouldwarp London still live. When Plato returns with stories of this lost world he is put on trial for corrupting the youth by means of lies and fables. Are their lives part of some greater reality? And, if they learn to doubt, perhaps they will be able to recognise a truth beyond that of their own world. All will depend upon the judgement of Plato by his fellow citizens.