Man-about-town James Tynewood pays for an expensive diamond. His cheque bounces and he disappears. His solicitor employs private eye Marjorie Stedman to find him. When Tynewood is found dead on the River Thames shore, the mysterious "South Africa Smith" appears and offers to help Stedman find the killer.
The Monthly Film Bulletin wrote: "Freely, and foggily, adapted version of an Edgar Wallace novel, featuring a private "eye" heroine in Hazel Court who waves her good breeding about like an enormous flag. The director's idea of high-life and low-life in Chelsea suggests that he has himself led a very sheltered existence."[3]