A womanizing matinée idol is found strangled in his dressing room. The door is locked from the inside and there is no other way into the room. He had been having an affair with his leading lady, while his actress wife is doing the same with the stage manager. Everyone, including a young actress who had been fired from the play, and an old actor now relegated to a stage-doorman, has a motive.The explanation for the murder lies within the script of the play.