Evidence that clears the name of a boy sentenced for killing his adopted mother arrives too late to save his life
- so who did kill her? Dr. Arthur Calgary takes a ferry across the Rubicon River to Sunny Point the home of the Argyle family. A year before the matriarch of the family was murdered & a son Jack was convicted & sentenced to spend the rest of his life in prison. Throughout the trial Jack had maintained his innocence claiming he was hitchhiking on the night of the murder & he had been picked up by a middle-aged man in a dark car. Unable to locate this mystery man the police viewed Jack's as a lie. Calgary was the stranger in question but he arrives to late for Jack
- who succumbs to pneumonia after serving just six months of his sentence. Feeling a sense of duty to the Argyles Calgary is surprised when his revelation has a disturbing effect on the family
- it means one of the family is a murderer...