1923. When a young Cockney woman appears in Falmouth, Inspector George Bartlett and Constable Archibald Boase think she's harmless enough – until they're caught up in a cycle of mayhem and deceit. Unsure exactly how this woman fits into their enquiries, at various turns they are investigating her, searching for her, and worrying about her safety – and still can't decide if she is all she seems.

With death on their doorstep, strange visitors to the town, and a killer still on the loose, Bartlett and Boase have little time left to prevent further murders as their superintendent looms large in the background, waiting to take them off the case...