The Blackbird is a thief who uses a second identity when necessary. He lives above a cheap bar in the Limehouse district, where his alter ego The Bishop, is beloved among all guests. One evening, the police drop by looking for him after a robbery, and he flees to a vaudeville theater, where his ex-wife Limehouse Polly has an act. Since their divorce they have become bitter towards one another, but Polly is willing to admit that she once married The Blackbird 'because she saw the soul in him that he did not know he got himself'. Furthermore, she admits to her father that she is still in love with him. The Blackbird, though, has become infatuated by Mademoiselle Fifi Lorraine, another performer and Polly's rival. He gives her a gun as a gift, explaining to her that someone as pretty as her should have a pistol or a man to protect her. Fifi prefers a diamond collar, and turns to a much wealthier guest in turn, West End Bertie. The Blackbird catches him stealing a diamond collar for Fifi, but after a battle, he is the one handing it over to her. Nevertheless, Bertie wins her affection and takes her home at the end of the night. When The Blackbird finds out that Bertie and Fifi have become engaged, he poses as The Bishop to reveal to Fifi that Bertie is a crook. Bertie admits this, but twists the story to make him look sympathetic, thereby making Fifi fall for him even more. Seeing how the plan backfired, The Blackbird turns Bertie in to a Scotland Yard inspector. Before they can get him for robbery and murder, Fifi decides to help her fiance hide, something she afterwards reveals to The Bishop. Seeing how she is now involved, The Blackbirds changes his plans and, posed as The Bishop, offers Bertie a bed in his secret room. To drive them apart, The Bishop tells Bertie that he can not escape because the police are looking for him in the Limehouse district, and claims to Fifi that Bertie will escape that night, on his own. Fifi offers Bertie to go along, but when he responds that he is not going because of the police, she thinks that he is lying to her and starts an argument. During this, Bertie is set up to believe that Fifi told the cops on him, and she leaves in tears. Meanwhile, Polly finds out that the police are also looking for The Blackbird for killing a Scotland Yarder. Just as The Blackbird and Fifi are about to kiss, Polly drops by to share the terrible news. Realizing the setting she has walked in, she turns her back on The Blackbird, which causes him to respond in anger, thereby scaring off Fifi. At that moment, the police barges in. The Blackbird is able to dress himself up as The Bishop, but falls and breaks his back during the process, thereby actually becoming crippled. When Polly is asked to burn his clothes, she realizes that The Blackbird and The Bishop are the same. In the end, Fifi and Bertie are reunited. With Polly's help, The Blackbird is able to trick the police for a final time, but he dies in the aftermath.
