A murderer walks through a locked door, shoots the victim and vanishes. He kills again with the same gun in the middle of a street that has people at either end, yet nobody sees a thing and there are no footprints in the snow.
This seemingly unsolvable crime is the plot of The Hollow Man by John Dickson Carr and even though it was first published in 1935 it remains, to many, the definitive locked room mystery.
An even earlier example of this fictional form comes from 1841 via Edgar Allan Poe’s short story The Murders in the Rue Morgue, and since then it has been replayed countless times and yet each time the premise is broadly the same. To write a locked room mystery you need a corpse, a room which is locked (preferably from the inside) and the absence of any clue that might help identify the murderer.
The locked room mystery is not simply a test for the fictional detective, it is one of the biggest challenges that crime writers face and it has toppled many a budding ink jockey. The solution needs to be credible and incredible in equal measure, although if you’ve read Poe’s story you might argue that the solution leans heavily over to the incredible. What the locked room mystery does so powerfully is to split the genre from its traditional anchor point of the “whodunit” and focus instead on the “howdunit”. Therein lies the problem. Detectives solve crimes and in the case of murder, the objective is to solve the crime by finding the murderer. Normally the cause of death is obvious but detectives hit a wall, literally in the case of the locked room, with the howdunit. When “how” is more important than “who”, nothing makes sense.
Here is an example, let me know what you think. For a bonus point, can you tell me which fictional detective had to solve this crime?
It was a hot day in July. I was called to the house of a wealthy industrialist by his wife. She met me at the front door of the residence, escorted me into the study and there, lying on the floor, was her husband, quite dead. Shot, actually. Ballistics tests conducted several days later, proved that the path of the bullet began inside the industrialist’s chest, and travelled outwards…it is essential that a suspect be placed at the scene of the crime, and … it is difficult if not impossible to prove that someone fired the fatal shot from inside the man’s chest. It seems to me that a great murder, like a great wine, should be savored. Take the night, or the weekend for that matter. Allow it to sink into your thoughts, invade your dreams. Consider it. Ponder it. And then, if the answer is not obvious to you…
I’ll reveal the answer next time. Until then stay safe and lock the door…if you think that makes things safer…