Malcolm Warren, a young but valetudinarian stockbroker, is looking forward to a dull weekend when a telegram summons him to stay with his capricious old Aunt Catherine, who has shocked the family by marrying Hannibal Cartwright, a muscular garage owner many years her junior...
Tricked into delivering a fatal dose of poison to his wealthy aunt, Malcolm Warren, a conservative stockbroker, must solve the mystery of her murder before he becomes the prime suspect.