John Dickson Carr is known as the master of the locked-room mystery the impossible crime. But Carr also wrote short stories, radio plays, essays, introductions, and book reviews. S. T. Joshi has written the first full-length study of Carr s entire work and pays particular attention to this author s three best-known detectives: Henri Bencolin, Dr. Gideon Fell, and Sir Henry Merrivale."