During the filming of a scene in Tonart Studio's production of The Death Kiss , actress Marcia Lane identifies a fictional character to be shot by kissing him. After actor Myles Brent is actually shot, Leon A. Grossmith, the studio head who mildly mangles the English language, worries about the financial impact of the murder, and studio manager Joseph Steiner is concerned about publicity, while the common feeling on the set is that Brent should have been murdered long ago. Detective Lieutenant Sheehan and Sergeant Hilliker begin to investigate, while scenario writer Franklyn Drew, who loves Marcia and likes murder mysteries, irritates Sheehan when, with the assistance of Officer Gulliver, the bumbling chief of studio police, he discovers evidence that refutes Sheehan's conclusions. Suspicion is first raised about Chalmers, an alcoholic ex-head gaffer whom Brent had fired. After Chalmers' apparent suicide, which Frank proves is murder, Marcia is arrested due to circumstantial evidence, and Frank finds a love letter in Brent's pocket from Steiner's wife and a key from an inn up the coast. He investigates and learns of a fight the previous night between Brent and the man whose wife Brent took there. After Frank finds the man's scribblings and matches them to those found during a meeting attended by Grossmith, Steiner and director Tom Avery, he learns of a clue from Bill, the property man, which identifies the murderer. As the murder scene is being recreated, Bill is about to reveal the man's name, when the murderer, hearing the conversation through the sound man's earphones, shuts off the lights and climbs to the catwalks. After a chase he falls to his death, and when the lights are turned on, the company sees that Avery is the murderer. His wife sees the body and says she's glad he's dead.