Wealthy heiress Rachel Argyll is brutally murdered at her family estate, Sunny Point. Her adopted son, Jack, is arrested for her murder but is killed in a prison brawl before the case can come to trial. Eighteen months later, as her widower prepares to marry again, the mysterious Arthur Calgary arrives, claiming to be Jack Argyll’s alibi and throwing the true identity of the murderer in doubt.

Nobody at Sunny Point is willing to believe Arthur but he’s determined to prove that Jack died an innocent man. However, his alibi puts him in perilous danger of his own. As Arthur reveals more of his story, the Argyll’s secrets are exposed and the devastating events that led up to Rachel’s murder are revealed. The true identity of her killer is finally unmasked.