In the usually peaceful town of Eastvale, a simmering tension has now reached breaking point. An anti-nuclear demonstration has ended in violence, leaving one policeman stabbed to death. Fired by professional outrage, Superintendent ‘Dirty Dick’ Burgess descends with vengeful fury on the inhabitants of ‘Maggie’s Farm’, an isolated house high on the daleside. Inspector Banks is uneasy about Burgess’s handling of the investigation. But he has been warned off the case. Soon Banks realises that the only way he can salvage his career is by beating Burgess to the killer.