The Unpardonable Sin (1915)

Herbert Sloane meets Ruth Brewer and they are photographed together on an old tin type. Later the girl gives birth to a son, but Sloane has left her. Five years after Sloane marries Grace Howard, and they decide to adopt a boy. They go to a home and there adopt Frank, Sloane's own son. Ruth has passed away and later her father dies and there is a sale of his effects. Grace attends the sale and there she is shown the tin type taken years before and is told the story connected with it. She nurses her grief and determines to bring the boy up so that when the time comes his father can make amends to him. Frank grows up to be a splendid youth and falls in love with a young girl next door. His father objects to the boy, of questionable parentage marrying the girl and then it is that Grace produces the photograph.