Men of the Night (1926)

Mrs. Abbott, an elderly newspaper vendor in dire straits, is taken in by Rupert Dodds, an art dealer, and Dick Foster, his young companion, who see in her transparent honesty an excellent shield for illegal activities in their art shop, where they remold gold and silver articles. Mrs. Abbott soon grows fond of Dick, who calls her "Mother," and she promotes his love for Trixie, the bookkeeper; but she becomes suspicious of Dodds and Dick when she overhears them congratulating themselves over their recent success. Mrs. Abbott discovers that they are planning to rob the home of Lady Broderick, a wealthy customer, and she follows them to prevent the crime, but she is captured and held accountable for robbing the safe. She is tried and convicted just as Dick confesses and clears her of the crime; and in the belief that Dick will reform, the judge sets him free. It develops that Mrs. Abbott is the long-lost sister of Lady Broderick and is the heiress to an English estate. Dick and Trixie are married and spend their honeymoon in England.