When a mysterious invitation arrives for the redoubtable Miss Phryne Fisher from an unknown retired Captain Herbert Spencer, Phryne's curiosity is excited. Spencer runs a retreat in Victoria's rural spa country for the many shell-shocked soldiers of the first world war. It's a cause after Phryne's own heart but what does Spencer want from her? Meanwhile, Cec, Bert and Tinker find a young woman floating face down in the harbour near the wharves.

Could this be the missing friend of Ruth, Phryne's adopted daughter? With Detective-Inspector Jack Robinson seconded unwillingly to a special investigation, Mr and Mrs Butler with Detective-Sergeant Hugh Collins are left to shield Phryne's household from danger as Tinker, Jane and Ruth decide to solve what appears to be a heinous crime. Unaware of these happenings, Phryne and the faithful Dot view their rural sojourn as a short holiday but are quickly thrown into disturbing Highland gatherings, disappearing women, murder and the mystery of the Temperance Hotel. All test Phryne's resourcefulness in her search to save lives.

Disappearances, murder, bombs, booby-traps and strange goings-on keep Miss Phryne Fisher right in the middle of her most exciting adventure.