Knox got the part of a supporting actor in a play involving talented actors Roscoe Strapping and Gloria Blaise. Strapping had been engaged to Blaise, whom Knox idolized, but due to his debauchery, Strapping became more interested in Knox and eventually cheated on Blaise with her.
During the play, Knox went onstage but Strapping purposely bumped into her and told her to scream once the lights were off. She did as he told her and screamed but when a gunshot was heard and the lights turned back on afterwards, Knox saw the body of the lead actress and ran up to her only to discover she was indeed dead.
During the investigation, it was discovered she lied about the scream in the dark. Inspector Alfendi Layton was certain that Strapping had her scream because it was part of his improvised rush to pin the blame on the stagehand Bray Clegg.
When Strapping was cornered after his scheme was exposed, he admitted he shot Blaise with an actual gun instead of the replica, had Knox scream and knocked Clegg unconscious to place the actual gun in his hand. However, he insisted he did not know the guns were switched and demanded to know who was the real mastermind of the case. To Strapping's surprise, it was actually Blaise who switched the guns and purposely threw the fake blood squib switch away and wrote a note pointing to Strapping's affair with Knox. Layton supposed she'd become unstable with the revelation of her fiancé's affair.
Later, as Strapping temporarily became a janitor as his punishment for battery against Clegg, Knox performed with Clegg, his substitute, in a medieval-themed play.