Bath detective Peter Diamond is having woman trouble. His boss wants him to find the missing daughter of one of her friends. He is not enthusiastic. A woman calling herself his Secret Admirer wants to arrange a date in a pub. He tries ignoring her. And his colleague, sexy Ingeborg Smith, distracts the murder squad from their duties. No one ignores Ingeborg.

A young woman emerges from a coma. Who is she, and why was she dumped unconscious in a hospital car park upon a dark night? She is unable to recall anything, even her name. Then Ada Shaftsbury, a boisterous shoplifter she meets in a homeless hostel, takes up her cause and names her Rose.Peter Diamond is already investigating a suspicious death - a woman has plunged from the roof of Bath's Royal Crescent during a party and none of the guests seem to know who she is.

When a severed hand from the vault of Bath Abbey Churchyard arrives on Peter Diamond's desk, he is delighted to hear that, far from being a medieval relic, it is from the 1980s. But the vault is part of the house where Mary Shelley's Frankenstein was written, and a fanatical American professor is thwarting their investigation. Events are complicated even further when the professor's wife goes missing . . .