When nurse Hestor Latterly accompanies the elderly Mrs Mary Farraline on a short trip to London, her only medical duty is to ensure her charming patient takes her heart medicine. But Mrs Farraline dies during the night. When her missing brooch 'turns up' in Hester's possession she is arrested for theft, until a post-mortem reveals a lethal dose of medicine in Mrs Farraline's body, and the charge becomes murder. Inspector William Monk must find a killer amongst the aloof Farraline clan, and in a Scottish courtroom the family's secrets will be exposed - or buried for ever.