An American police detective, Priscilla Booth, inherits a house in Cornwall from her murdered cousin, but she must live there 30 days. Her lover, Mort Sinclair, a multi-disciplined criminologist comes down from Oxford to stay with her. Gradually they get drawn into the mysterious past of the murdered woman, as a new murder occurs. Their suspects include people who frequent the village pub and also TV actors and technicians who are filming a miniseries at a nearby manor. They hear stories of ghosts and smugglers and Priscilla finds herself the object of seduction by both a leading actor and a powerful producer. Priscilla and Mort learn more and more astonishing details about her dead cousin, Sylvia. Exploring a secret tunnel, she suddenly finds herself alone with the killer. Mort cultivates the local police inspector, who is impressed by Mort's reputation. However, this acts as a split between Mort and Priscilla, and the solution to the murder comes with Mort's clue-solving, plus some unexpected physical exertion from an unsuspected quarter. Now that the murderer is caught, Mort and Priscilla must endeavor to mend their fractured relationship.