Under promise of marriage, innocent Mary Ellen Ellis leaves her country home to accompany the experienced Walter Benton to the city. Mary Ellen finds herself in an underworld milieu, but she is able to influence burglar Bull Clark to reform, thus earning his undying gratitude. Clark is able to repay Mary Ellen when he rescues her from The Weasel, who has followed her to her apartment. When Benton returns and finds his wife and Clark together, a fight ensues between the two men in which Benton is killed by The Weasel. Clark is accused of the murder and sentenced to jail, but escapes and joins the Navy. Meanwhile, Mary Ellen is forced to live in shame until she is rescued by Jane Murray, an office assistant in an East Side infirmary. There Mary Ellen meets Dr. Graham, Benton’s cousin, and the two fall in love. Fear of the doctor’s scorn for her past life forces Mary Ellen to leave, and she is abducted by The Weasel and imprisoned in a vacant room. A newsboy informs the doctor of her whereabouts, and through the doctor’s efforts Mary Ellen wins her freedom as well as his love.