Flynn becomes a millionaire and moves his family out of the tough New York City tenement known as "Hell's End." As the years pass, Mary Flynn and her brother Jimmie lose track of their childhood friend, Jack Donovan. While visiting her old neighborhood, Mary renews her acquaintance with Jack, now the leader of a notorious group of gangsters and crooked politicians. When their conversation arouses the jealousy of Belle Burns, she provokes a fight between Jack and his rival for power, Hank Dillon, which leaves Jack seriously injured. Following his release from the hospital, Jack joins Mary in her Red Cross work and the two fall in love. Jack defeats his rival in a fight and regains his prestige, but soon abandons the gangsters to finds happiness with the girl he loves, working to improve conditions in Hell's End.