PHILIP MacDONALD – Persons Unknown. Doubleday Crime Club, US, hardcover, 1931; Collins Crime Club, UK, 1932, as The Maze. Paperback reprint: Collins #162, UK, 1938, also as The Maze.

   In his introduction to this documentary novel, Philip MacDonald says: “In this book I have striven to be absolutely fair to the reader. There is nothing — nothing at all — for the detective that the reader has not had. More, the reader has had his information In exactly the same form as the detective — that is, the verbatim report of evidence and question.”

   Anthony Gethryn is vacationing in Costa del Chica, Spain, when he receives from Assistant Commissioner Sir Egbert Lucas, C.I.D., the transcript of the coroner’s inquest into the death of Maxwell Brunton. Brunton had been murdered in his study one night, a crime that could have been committed only by someone residing in the house.

   Brunton, according to the testimony, was a philanderer and a man easily given to anger, but he also had many good points. Of the residents, some, particularly Brunton’s wife and son, had strong motives for doing him in.

   Others had weak or no discernible motives. The police investigation and the testimony at the inquest lead to no conclusion as to who might have committed the murder and why.

   It was Sir Egbert’s hope, although not his expectation, that Gethryn would be able to spot the murderer. Gethryn’s usual rule is to look for “oddnesses” in a case when he can find them; in this one, he finds many oddnesses.

   So Gethryn turns the process upside down and spots the culprit, who, he points out, will never be convicted by an English court.

   I didn’t spot the killer, but I should have, although the motive, unusual for a book of this vintage, would still have eluded me. Mystery novels don’t come any fairer-play than this one.