Moonlight Murder takes place virtually in its entirety at the Hollywood Bowl. Despite dire warnings by a sinister mystic (Pedro de Cordoba), opera-star Gino D'Acosta (Leo Carrillo) insists that he will sing in the Bowl's current production of Il Trovatore. He gets no farther than the "Anvil Chorus" before he drops dead in full view of the audience. It turns out that D'Acosta was murdered, placing everyone in the cast under suspicion. As night segues into morning, detective Steve Farrell (Chester Morris) -- whose past mistakes have put him in hot water with his boss -- teams up with lady-scientist Toni Adams (Madge Evans) to piece the clues together. The hot-potato issue of euthanasia is raised during the course of Moonlight Murder, and as a result the film turns out to have one of the most sympathetic and reasonable culprits in "B"-picture history. Trivia alert: One of the suspects is played by Duncan Renaldo, who later co-starred with "victim" Leo Carrillo on TV's The Cisco Kid.