The Black Spectacles by John Dickson Carr

Carr's ingenious detective, Dr. Gideon Fell, usually solves impossible 'locked room' mysteries, but this 1939 puzzle is more a case of deduction—where each eyewitness to the murder saw something different.

Marcus Chesney, his brother Dr. Joe, friend Professor Ingram, his young niece Marjorie, and her new beau George Harding, face vicious gossip in their town of Sodbury Cross, where Marjorie was accused of placing strychnine-laced chocolate creams in Mrs. Terry's sweet shop. Several were ill; one died. Did the poisoner do it merely for the pleasure of indiscriminate killing?

Marcus makes a study of crime, and stages an after-dinner psychological test for the group. He asserts witnesses are notoriously unreliable, and he is about to be proven right. Sitting at his desk, his disguised business manager, Mr. Emmet, was supposed to pretend to poison him, but someone unknown took his place and fed Marcus strychnine, while Emmet lay knocked out cold outside. George, Marjorie, and the Professor each witnessed the murder, yet can't agree on anything that happened.

Inspector Elliot of Scotland Yard is called to investigate. The staged scene was a series of traps with a set of questions Marcus was going to pose: what time did it take place? What was on the table? How tall was the intruder? None can agree on the facts, yet all of them are correct. No one left the room at any time, yet one must be a murderer. Halfway through the novel, Elliot brings in the fast-moving mind of Dr. Gideon Fell to discern the discrepancies in this box of tricks, the solution of which could solve the chocolate poisoning case.

Known as one of the most popular Gideon Fell cases, and one of Carr's best, the technical aspect of deciphering clues from every angle can get a little tiring for the reader, but of course, the solution is sound. This was dedicated to Powys Mathers, who created puzzles under the name Torquemada, and wrote Cain's Jawbone, the classic brainteaser mystery of which the page order has been shuffled. Also known in the US as The Problem of the Green Capsule, this was recently republished by British Library Crime Classics.

1939 / Tradeback / 304 pages