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 . . .

Highly suspicious of the professor, but unable to prove anything, Diamond concentrates on trying to identify the remains, with shocking result. But before he can get any further, the owner of Bath's largest antique emporium is brutally murdered - and the last person to see her alive was the Professor.