John Willoby is a prison officer: tough, stolid, unimaginative - until he starts hearing the voices and the strange sounds: the clash of swords, the thunder of hooves. Willoby suspects he's going mad. His wife and daughter know he is. Then the hallucinations begin, visions of a wild, strange, primitive world that draw him in until there is no going back. In that world a city is being built and a bastard son is plotting to usurp his father's throne by bloodshed. And Willoby, unknowing, is part of the plot. For Willoby is not mad.