The John Dickson Carr Treasury (hardcover)
This was a Dr. Gideon Fell locked room mystery.
Professor Charles Grimaud appears to be a self-made man. Intelligent, well-liked, respected, and comfortably in social standing. Then while at the Warwick Tavern an unexpected and very unwanted figure appears. Pierre Fley is the Professor's long lost brother. In the midst of the Professor's discussion, he aims threats about another brother. The other brother who died under strange circumstances holds the key to a door that the Professor never wanted to be opened. Behind that door lies a secret that best remains locked away.
Pierre goes on to inform Grimaud that the other brother will rise from his grave and pay him a visit.
Threatening letters follow and then the night of the visit Grimaud is found shot inside his locked study alone.
I appreciate the old fashioned way Dr. Fell has in uncovering each clue to solve and explain this mystery to his friends: Superindendent Hadley and Ted Rampole with his wife Dorothy from America. Pictures of 2 scenes are included to aid the reader.