When a young man washes up, naked, on the sands of St Piran in Cornwall, he is quickly rescued by the villagers. From the retired village doctor and the schoolteacher, to the beachcomber and the owner of the local bar, the priest's wife and the romantic novelist, they take this lost soul into their midst. But what the villagers don't know is that Joe Haak has fled the City of London fearing a worldwide collapse of civilisation, a collapse forecast by Cassie, a computer program he designed. But ...