The Danger Girl (1926)

Wilson Travers and his brother, Mortimer, live singular lives, interested only in their respective hobbies of collecting rare gems and even rarer tropical fish. The police learn that jewel thieves are planning to knock over the Wilson gem collection, and the brothers take precautions. One evening, Marie Duquesne, dressed as a bride, appeals to the brothers to help her avoid a distasteful marriage to an old man. The brothers let her stay the night; Mortimer resents her presence, but Wilson falls in love with her. The following morning, the butler tells Wilson that, suspicious of Marie's nocturnal prowling, he has called the police; and a policeman soon arrives and takes her into custody. That night the butler is prevented from looting the safe by Marie, who has returned to the house. Marie, who is a detective, sees to the arrest of the butler and then turns her attentions to Wilson.