My choice for today's Forgotten Book is another title by John Dickson Carr that has happily found a fresh life thanks to the enterprise of James Prichard's Langtail Press. This is The Problem of the Green Capsule, which was first published in 1939. Dickson Carr wanted to call the book The Black Spectacles, and that was the title used in the UK (and I think, given the storyline, he was right and his American publishers rather missed the point.)
After some scene setting in Pompeii, the action switches to a quintessential English village, Sodbury Cross. Someone's been poisoning chocolates, and an attractive young woman called Marjorie Wills is a possible suspect. Her rich uncle, Marcus Chesney, a man with an ingenious turn of mind but a habit of penny-pinching, dreams up an elaborate charade intended to cast light on the mystery. Of course, in Golden Age detective fiction, a tendency to over-elaborate is a fatal characteristic of both murderers and victim alike, and so it proves here. Needless to say, Marcus ends up dead, poisoned by the eponymous green capsule.
Another murder occurs, and Dr Gideon Fell, who has been taking the waters at Bath, is called in to assist the baffled police. This is not a "locked room mystery" of the type for which Dickson Carr was renowned, but there is some jiggery-pokery with a clock and with the film of Marcus Chesney's charade which contribute to the puzzle. As always with the best of John Dickson Carr, the mystery is ingenious and atmospheric, and I did not guess the solution.
One of the features of this novel which particularly interested me was the way in which Carr used elements from real-life murder cases to cast light upon the events of the story. He was fascinated by true crime, and made excellent use of his knowledge. I'm certainly planning to read more of his books to see whether this was a recurrent feature of his work.