MacDonald was actually a successful writer throughout the 1930s, writing a string of mystery novels often featuring amateur sleuth Anthony Gethryn. His best known novel was written in 1959, and was later made into a film - The list of Adrian Messenger.
He wrote the screenplay for many of the Charlie Chan and Mr. Moto mystery films, was an uncredited adapter of James Whale's brilliant Bride of Frankenstein (as was R.C. Sherriff), and co-adapted Daphne du Maurier's Rebecca for Alfred Hitchcock (the screenwriters were nominated for Best Screenplay at the Oscars, where Rebecca won Best Film. Hitchcock, notoriously, never won a Best Director Academy Award).
Sadly MacDonald is today almost forgotten, and this seems a great shame to me. The noose may not be the greatest crime story you've ever read, but there's a lot about it that's very good. Gethryn himself is a lovely character with a feisty wife; a couple who, I suspect, may have been an influence of Dorothy L. Sayers' Peter and Harriet. The story itself is well plotted, and the suspense element is very clever, and would, I suspect, at the time have been quite unusual.
Anthony Gethryn is persuaded by his wife to investigate a murder conviction. The murderer will be hanged in 5 days time, but his wife, Selma, is convinced that her husband could not have committed the crime. Her plea that a cowardly attack from behind would not be the way her husband would kill someone, sounds laughable; but her faith in her spouse inspires Gethryn's own wife to persuade her husband to look at the case again.
Initially it seems that the jury have got the correct verdict, but then Gethryn starts to spot small flaws in the case, which point him in the direction of a most unlikely murderer. But will he be able to prove his point before an innocent man is forced to walk to the gallows?
Yes, there's the odd leap of faith, but over all this is a well plotted example of Golden Age crime fiction at its best. It may lack the verve of Christie, or the characterisation of Sayers, but it's great fun, and well worth reading. In fact Harper Collins have now reprinted several of the Gethryn mysteries, and they're already marked up on my "to be borrowed" list. Don't forget MacDonald, he's a worthy member of the Golden Age Crime circle.