Professor Morley is drawn into a murder investigation at the Colchester Oyster Festival when the mayor dies suddenly during a civic reception. In October 1937, Professor Morley travels to Essex to continue his history of England, accompanied by his chaotic daughter Miriam and his despondent assistant Stephen Sefton. While attending the Colchester Oyster Festival as an honorary guest, the mayor dies unexpectedly, casting suspicion upon his fellow councillors. Morley must navigate the complexities of the festival and the ensuing investigation to uncover whether the death was accidental food poisoning or deliberate murder.

The Daily Mail has praised Ian Sansom's creation, Professor Morley, suggesting he is poised to become a notable figure in English crime writing. The novel is described as beautifully crafted, inviting readers to sample the character's early adventures. The premise sets up a classic mystery within a specific historical and cultural context, promising an engaging narrative for fans of traditional detective fiction. The inclusion of personal subplots involving Morley's daughter and assistant suggests a character-driven element alongside the central investigation.