Backstage at the Causton Amateur Dramatic Society's production of Amadeus, nerves are fraying. On top of the fractious cast hierarchy imposed by Harold Winstanley, director and would-be impresario, cast member Esslyn Carmichael suspects his wife is having an affair with the leading man. And where better to settle scores than the stage? On opening night, Chief Inspector Tom Barnaby attends, purely as a member of the audience. But when someone turns Esslyn's final grand gesture into a very gruesome coup de theatre, Barnaby suddeny finds himself centre stage...