Let X be the Murderer was published in 1947.
It is a bleak November morning when Sergeant Martin, Inspector
Charlton's stalwart sidekick, receives an agitated phone call from Sir
Victor Wallingham claiming that a ghost attempted to strangle him in the
night. When Inspector Charlton follows this up, he is blocked at every
turn, but even so, when the following night does actually end with the
discovery of a body, he is not expecting it.
"It is confidently predicted that the denouement to this exciting and
tautly written tale will cause the reader as great, if not so painful, a
surprise..." -Classiccrimefiction.com