My favorite mystery is "Rim of the Pit" by Hake Talbot. It contains a number of puzzles: a locked room murder, a ghost materializes at a seance, a murderer appears to be able to fly, plus others. Piled on top of each other, Talbot still managed to make his tale, not quite believable, but plausible. Paul Halter writes impossible crime stories, and this one just seems like too much of a good thing. Seven impossible murders occur, and while police are baffled, Owen Burns, amateur sleuth, does manage to unravel the clues and in the end explain how each of the crimes was committed. But Owen is not a particularly engaging character, and another major player, a young woman, is constantly referred to as an incredible beauty, which gets old. Not a complete failure, but it was making my head ache near the end.