There Are No Villains.

In San Francisco, California, Rosa Moreland of the Secret Service is unable to obtain evidence against suspected opium smuggler George Sala. She then advises Detective Flint of her plan to develop a relationship with John King, an impoverished, disabled ex-soldier who Rosa met in George's office. After claiming to have lost her home in a fire, Rosa is invited to stay in John's modest flat. He receives money from a mysterious source, enabling them to afford a more expensive apartment, and they soon fall in love. Although Rosa secretly witnesses John receiving a package from George, she tells the skeptical Flint that her lover is above suspicion. John agrees to end his association with George if Rosa will marry him, and, realizing that a wife cannot legally testify against her husband, she agrees.