Ruth Raymond works on the telephone switchboard of a large NYC office building. One day, a private detective informs her that she is actually the daughter of railroad tycoon Luke Carson, and that she had been kidnapped as a baby 14 years ago by Luke's vindictive brother Elwood, and placed with strangers.
The owner of a large mansion in the country throws a costume party for some of his friends. However, the party turns sour when he is found stabbed to death in a closet.
Father, son Kentaro and daughter Ochiyo, who live on the banks of the Sumida River, regain their love for each other after family discord and separation.