These Names Make Clues (1937) – E. C. R. Lorac
A chance encounter with publisher Graham Coombe leads to Chief Inspector Macdonald getting an invite to his "Treasure Hunt"; a party where attendees must solve cryptic clues in order to find treasure. With all the guests apparently unknown to each other and going under literary pseudonyms, the evening gets off to a good start - until the lights go out, and a body is found in the telephone room. The dead man is Andrew Gardien, mystery writer, and something of a mystery himself. Further…