Lincolnshire, England. June, 1928. When three freshly-buried bodies are unearthed in the front yard of a rented cottage, DCI Henry Johnstone, a specialist murder detective from London, is summoned to investigate. Two of the victims are identified as Mary Fields, known to have worked as a prostitute, and her seven-year-old daughter Ruby. But who is the third victim and what was he doing at the cottage?

Johnstone is determined to do things by the book, but his use of forensic science and other modern methods of detection soon ruffles feathers. Frustrated by the unhelpful attitude of the local constabulary, Johnstone fears the investigation is heading nowhere. Then he's called out to another murder . . .