秘密機関
Like "The Secret Adversary", "The Man in the Brown Suit" is less a novel of pure detection than it is a thriller typical of its period. It follows the adventures of Anne Beddingfeld who witnesses a man killed in a subway station and the man whose appearance frightened him, as she becomes involved in a world of diamond thieves, murderers, and political intrigue in this tale set in South Africa. Colonel Race makes his first appearance in the novel; he later appears in "Cards on the Table", "Sparkling Cyanide", and "Death on the Nile".