A craft centre in the old mill at Morton Fendle is losing money. Several locals have invested in the business and believe they have been swindled by Alan Hollingsworth, the man behind it. When Hollingsworth's glamorous wife Simone goes missing, Barnaby believes she has been kidnapped and puts Hollingsworth under observation. However, Hollingsworth evades the police, carrying a bundle of cash, and a woman neighbour who follows him to his rendez-vous is killed in a bizarre road accident. Then Hollingsworth is found dead, and Simone turns up alive. Barnaby guesses she and a friend faked the kidnapping, but he can't prove it.
The body of Agnes Gray, a woman who loved only animals, is found in the river - but she did not drown. And then her cousin Esslyn Carmichael is tricked into killing himself on stage during an amateur production of the murder mystery Amadeus.
Barnaby has to get to grips with clues which include adultery, dramatic ambition, stolen religious art, and large donations to animal charities, before unmasking a killer who proves to be mad.
Meanwhile, love begins to blossom between Cully Barnaby and Nico Bentley, one of the cast of Amadeus...