''The Cornish Fox'' by C. H. B. Kitchin serves as the fourth and final installment in his acclaimed detective series featuring Malcolm Warren, who first appeared in Death of My Aunt, and then reappeared in Crime at Christmas and Death of His Uncle. He is a stockbroker who reluctantly acts as an amateur sleuth. Malcolm Warren returns twenty years after his debut in Death of My Aunt (1929). Like the author himself, Warren is a stockbroker and a bit of a dilettante. The story is set in a remote part of Cornwall, a region Kitchin knew intimately from living there near the Helford River. The narrative explores a community of post-war English settlers living in an environment where locals still view outsiders as foreigners. The mystery plot alternates between a social study of this isolated community and a mystery sparked by malicious poison-pen letters signed by "The Cornish Fox"!