Diana Baring (Nora Baring) is accused of murder. She does not remember what happened; but her defense in court of being in a fugue state does not go with the jury. But one juror, Sir John Menier (Herbert Marshall) still has his doubts. He was convinced to vote guilty, but he still believes the woman. She doesn't remember what happened. He wants to find out.
So he begins his own investigation. She was the only one in the room. He interviews the owners of the apartment Doucie and Ted Markham (Phyllis Konstam and Edward Chapman). They do not give much information, but Ted decides to investigate with him. Miss Mitcham (Marie Wright) isn't much help either.
They go to the theater where they work and find more clues there. Here are people who are on the edge of society--circus performers. Also people who can get into tight spaces, one being an acrobat. Baring has been hiding the identity of a man in the room. But she does mention he is half caste (bi racial). At the circus Menier discovers Handel Fane (Esme Percy). He is suppose to be biracial, and the murder victim had discovered this so he kills her to keep her silent. It was taboo to be biracial during this period and would have reuined his career. The victim and Baring were in deep conversation so he was able to sneak in the window, go past them and strike a blow with the poker.
Menier traps him through the guise of reading a script for a theater production. The script has the last page blank, and Menier recruits him to finish it, which he does describing how he completed the murder before killing himself.
Fane is a male performing a trapeze act dressed as a woman. He also hides his identity, as well as his involvement in the murder. When this all comes out it is more than his psychic can take and he hangs himself from the trapeze bar.
