Wealthy philanthropist Rachel Argyll is murdered at her family estate Sunny Point. Her adopted son Jack Argyll, a young delinquent, is arrested for her murder. He vehemently protests his innocence. Eighteen months later, Dr Arthur Calgary, a mysterious scientist, walks onto the velvety lawns of Sunny Point claiming to have just returned from an expedition to the Arctic. Even more extraordinary is his claim to hold the alibi that can prove Jack’s innocence.