Mariana, a typical child of the streets, and an orphan, sells newspapers for a living. One evening she accidentally encounters Northrup, a prominent attorney, and they become friends. Hinky, Mariana's brother, a pickpocket, pursued by the police, comes home while Northrup is there. Mariana hides Hinky and she and Northrup deny any knowledge of his whereabouts. Northrup, fascinated with the girl, and pitying her somewhat, induces his sister, Mrs. Lacey, to give Mariana a position as maid in her home. However, in the midst of her happiness at the home of Mrs. Lacey, Hinky swoops down upon her. With threats and blows he forces Mariana to permit him to enter the home and rob it. Mariana, feeling she cannot impose any longer on the kindness of her friends, leaves. Six months later Hinky is a prominent figure in the underworld, and Northrup is prosecuting Henry Hay, the president of the traction company of the city, who has put over several shady deals. Hay decides that he must secure Northrup's papers. He engages Hinky to steal them. In the midst of the plotting, Mariana comes into the room and overhears all. Northrup is sent a note telling him to come to a certain address at 4 o'clock sharp that afternoon. Mariana goes to the police station. A detail of police are sent to Northrup's aid. Exactly at 4 o'clock Northrup is bound and gagged by the gang. The police break into the house and capture Hinky and his confederates. Mariana frees Northrup.