May 1796, and former Foreign Office clerk Laurence Jago and his larger-than-life employer, the journalist William Philpott, have escaped America - and Philpott's near imprisonment for libel - by the skin of their teeth.

They return to Laurence's hometown of Helston, Cornwall, in the hope of rest and recuperation, but instead find themselves in the middle of a tumultuous election that has the inhabitants of the town at one another's throats. Only two men may vote in this rotten borough, and when one of them dies in suspicious circumstances, Laurence is ordered to investigate on behalf of the town's political patron, his old master the Duke of Leeds. Then the second elector is poisoned and suspicion turns on the town doctor, the gentle Pythagoras Jago, Laurence's own cousin.

Suddenly Laurence finds himself ensnared in generations of bad blood and petty rivalries, with his cousin's fate in his hands...