A quiet animal-loving woman, Agnes Gray, is found drowned in Ferne Basset. Her cousin Esslyn Carmichael is due to appear in Causton Amateur Dramatics' showing of Amadeus which Joyce Barnaby is taking part in. As her husband DCI Barnaby and Sergeant Troy investigate the death, tensions are running backstage at the theatre. But the opening night defies all expectations as someone turns Esslyn's final act into a true coup de theatre.
The Causton Players are getting ready for their production of Amadeus when Barnaby tells one the lead actors Esslyn Carmichael (Nicholas Le Prevost) that his cousin Agnes Grey (Denyse Alexander) has been murdered. The body of Grey, 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 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. Esslyn is married to the young Kitty (Debra Stephenson), and is divorced from heavy-drinker Rosa (Sarah Badel). Avery Phillips (Nick Woodeson) and his partner Tim Young (Richard Huw), who own the local bookshop, are both involved in Amadeus. The play's director is wealthy Harold Winstanley (Bernard Hepton), who is married to Doris (Angela Pleasence), the stage manager is shy Deidre Tibbs (Janine Duvitski), who is rumoured to be in a relationship with actor David Smy (Ian Fitzgibbon), whose father Colin (Geoffrey Hutchings) works backstage.