When out walking on Arthur's Seat, high above the city of Edinburgh, Rose McQuinn discovers the body of a woman in the ruins of St Anthony's Chapel. She is even more astonished when on her return to the scene there is no evidence of either the victim or the local constable who had taken down Rose's story at the scene of the crime. Turning to her would-be lover, Rose finds the normally sympathetic Detective Sergeant Jack Macmerry doubtful over the validity of her story, especially as the Edinburgh City Police have received no record of the dead woman or P C Smith, the policeman who had originally come to Rose's aid. Although it would appear that both corpse and constable have disappeared into thin air, Rose is convinced that she had come across a murder that afternoon, yet her ensuing discreet investigation into the mystery of the vanishing corpse soon turns into a more dangerous pursuit. Is there a link between Rose's bogus constable and the disappearance of a policeman's uniform belonging to the local amateur opera group, currently performing The Pirates of Penzance? Further complications arise when one of the cast members reports a missing wife; could she be Rose's disappearing corpse? Rose is unshakeable in her belief that there is a link between the two cases, and her determination to find a solution to this mystery leads her to a terrifying situation where she finds herself well rehearsed for the role as the murderer's second victim.