Tour de Force is a 1955 mystery crime novel by the author Christianna Brand. It was the sixth novel in a series featuring the fictional police detective Inspector Cockrill. It was the last full-length novel in which Cockrill appears, although he features in some short stories. His sister Henrietta also features in the 1957 novel The Three Cornered Halo which uses the same setting as this work. Additionally, the minor character Mr Cecil from Death in High Heels (1941) appears in a more prominent role. Source: Wikipedia (en)