CARTER DICKSON – Seeing Is Believing. William Morrow, US, hardcover, 1941. Heinemann, UK, hardcover, 1942. Paperback reprints include: Pocket #386, 1946; Berkley F1282, 1966; Zebra, 1990.

   A small gem from the Golden Age of Detection, no doubt about it, even though the setup involves hypnotism and whether or not a person can be commanded to kill someone while under the spell. More specifically, though, this is the case of someone switching a knife with a rubber blade with a real one, one that does the job very nicely — but in a room full of observers watching intently but who never saw the switch being made.

   Sir Henry is in fine form with this one, full of mysterious hints of what he knows but without ever quite telling until the end. There is the usual bit of grand buffoonery as well, as he spends his spare moments dictating his memoirs to a poor fellow who soon wishes ne never signed up for the job.

   Unfortunately while the solution to the mystery sounds possible, if you think about it more than once, the killer really had to have been quite lucky to have pulled it off. John Dickson Carr / Carter Dickson was also a master of using exactly the right word in his stories, often just managing for them to qualify as “fair play” puzzles.

   Take this line, for example, which comes early on. [WARNING: Plot Alert Ahead]. When he uses the sentence “That was the admitted fact,” which is precisely correct, but not in the way the reader reads it the way Carr/Dickson wants him to. Clever? It’s the key to unraveling the whole case.

   And if you think this is a complaint, you’d be wrong. It’s like a wicked clue in a crossword puzzle, one if you see it the right way, it’s easy. Otherwise, not. Misdirection? It’s the name of the game.