The Crime Readers' Association

John Bayliss – The Mystery of the Locked Room Mystery

10th April 2015

We’ve all read them. We’ve all (hopefully) been mystified by them, too—those crime stories where how the crime was committed is as much of a puzzle as who committed it.

They’re generally called ‘Locked Room Mysteries’ although they don’t necessarily need a locked room to make them work. Just as effective is a field of fresh snow, or a pristine sandy beach, over which only the victim’s footprints are visible. The victim does not even have to be obviously murdered, either—some Locked Room Mysteries start with an apparent suicide or death by natural causes, and it’s only the suspicions of a nosy detective that uncovers the truth. All that’s needed is no (apparent) physical way for the murderer to carry out the deed. Yet the deed obviously has been carried out and here is the evidence (a corpse) to prove it.

If the Locked Room Mystery sets a challenge for the reader, it sets an even bigger one for the author. The author must first put themselves into the mind of the perpetrator by devising a cunning modus operandi and carefully concealing the evidence. Then they must put themselves into the mind of the detective and carefully unravel all that good work, seeking out the one loophole that gives the game away. Finally, they have to put themselves in the place of the reader, and make sure that the clues are clear enough to be noticeable but not so clear as to be obvious. (That is the hardest bit.)

Another challenge is that Locked Room Mysteries only have a limited set of possible solutions, and the author has to be careful to chose one that hasn’t been ‘done’ too often, or at least disguise it so well that it appears to be an original ploy. John Dickson Carr (considered by many as a master of the Locked Room Mystery) provides a comprehensive analysis of the possible methods in his novel The Hollow Man. I won’t recapitulate his entire thesis here, but he does narrow the possible solutions down to eight basic types (although, in the novel itself, Dickson Carr cunningly provides a solution that doesn’t actually fit into his classification). The solution must be simple enough to be believable, yet not so simple as to be obvious. If the victim died from banging his head on a low beam rather than being struck with a blunt instrument, then the plot could unravel into a disappointing anti-climax.

Why do authors still write Locked Room Mysteries? Well, there’s the challenge for one thing—one that, for a crime writer, is on a par with climbing Mount Everest for a mountaineer. And although these days some publishers may turn up their noses at what they believe to be ‘old hat’ they are still hugely popular with readers. So long may the Locked Room Mystery thrive.


Now, where did I put that key?


Go back to Blog

Join the CRA

Joining the CRA is FREE. There are no lengthy forms to fill out and we need nothing but your email. You will receive a regular newsletter but no spam.