In the dying days of the nineteenth century, the small Russian town of Zavolzhsk is shaken out of its sleepy rural existence by the arrival from St Petersburg of a Synodical Inspector with a hidden agenda and a dangerously persuasive manner.

Meanwhile, in the nearby country estate of Drozdovka, one of the prized white Bulldogs - prized because of its one brown ear, and its propensity to drool - belonging to the cantankerous lady of the house has been poisoned. The old widow has taken to her bed, sick with fear that her two remaining dogs may face a similar fate, and the many potential beneficiaries of her will wait fretfully to see whether or not she will recover.

Sister Pelagia: bespectacled, freckled, woefully clumsy and astonishingly resourceful is summoned by the Bishop to investigate. But her investigation soon takes a far more sinister turn when two headless bodies are pulled out of the river on the edge of the estate.