Allingham, Margery: The Crime at Black Dudley
It is 1928 and Albert Campion, the misleadingly vapid-looking detective, is introduced to readers for the first time. He then appears in another 18 novels and many short stories over the next 30 years. At a house party at remote Black Dudley the host, Colonel Gordon Coombe dies – supposedly of heart failure during the Ritual of the Black Dudley Dagger. There are some secret documents that some crooks want and that Campion has, but the crooks are too ruthless and smart for the Campion and the rest of the house party. When it is revealed that precious document has been burned the crooks imprison the guests, who get rescued by the local Hunt, and all is well. But is it? Who killed Uncle Gordon and why?