After Mary Carroll's husband learns that she has had an affair, he challenges her former lover to a duel and is killed. Mary is thrown out by her husband's wealthy family and separated from her little boy, John Carroll, Jr. Years later, John Jr. falls in love with Ruth Fulton, the daughter of the horse trainer for Rex Burleigh. When her father dies, Ruth accepts Rex's offer to care for her, but she leaves the expensive apartment he has provided when she learns his true motives. Boxer and former jockey Kid Dugan kills Rex because he also loves Ruth. Ruth later becomes a secretary to Mary, unaware that she is John Jr.'s mother. Ruth leaves after Mary learns of her involvement with Rex, then Mary acknowledges to John Jr. that she is his mother. John Jr. introduces Ruth to his mother, who advises her to confess everything to her son. Ruth does so, but John Jr. refuses to believe in her innocence. When John Jr. is set up to lose on a big horse race, Ruth rushes in and rides the horse to victory and is forgiven by John Jr.