An interesting and well-written experimental sort of detective novel.
Roger Sheringham has established a small club for people interested in criminology. His latest idea is for them all to investigate a recent unsolved crime ("The Poisoned Chocolates Case") during the course of one week. On successive evenings, each member will then take the floor to share his or her conclusions in hopes that somewhere along the line they will solve it and hand it back over to the police.

What follows is a fairly amusing indictment of traditional detective stories. In many such books, the reader is primed to accept that the detective's deduction on any given fact is the only possible conclusion. But in this book there are as many deductions as there are people, and all of them plausible in their own way.
The only flaw in this structure is that when you finally reach the "real" solution, you are still left with a nagging feeling that it's only one of many possibilities...
Which maybe was the point.
And indeed a couple of other authors wrote additional solutions in later years, which are evidently part of the newest edition of the book. It might be worth tracking down just to check out those other solutions.


A few excerpts to show off the occasional flashes of humor:

Roger sped to the rescue. The combatants reminded him of a bull and a gadfly, and that is a contest which it is often good fun to watch. But the Crimes Circle had been founded to investigate the crimes of others, not to provide opportunities for new ones.


The motion was carried unanimously. Mrs. Fielder-Flemming would have liked to vote against it, but she had never yet belonged to any committee where all motions were not carried unanimously and habit was too strong for her.


"A friend of Mrs. Bendix's then. At least," amended Mrs. Fielder-Flemming in some confusion, remembering that real friends seldom murder each other, "she thought of him as a friend. Dear me, this is getting very interesting, Alicia."