A spirited, self-absorbed young actor sits on a window-ledge posing for a photograph, and is then seemingly pushed to his death…with more than one witness independently swearing there was no one there to push him, that he appeared to have been “propelled forward”. The sense of menace builds when investigators realise that a very similar death had occurred 50 years earlier in the same old house, and that – more recently – a young girl fell off a nearby cliff after being pushed by an “invisible man”.

All this is happening in the misty Devon moors in the 1930s, and there is much talk of ancient legends, including a story about the Devil’s playing cards being scattered around a crime scene, and a headless horseman who may have been seen on one of the murder nights.

With such a premise and setting, it’s easy to think that Paul Halter’s 1993 novel Le Diable de Dartmoor – translated into English by John Pugmire as The Demon of Dartmoor – has supernatural underpinnings. Reading the story, we find that even the more level-headed residents of Stapleford village – among them a doctor and a teacher – think mystical forces could be at work.

But as it turns out, the solution to these mysteries is a wholly rational one, rooted in the human capacity for crime. And by the time the novel ends, most aficionados of the “locked-room” or “impossible crime” tale will agree that the Frenchman Halter (not all of whose books are available in translation) merits his reputation as a successor to the celebrated John Dickson Carr, who specialised in this tricky subgenre of crime fiction.


The term “locked-room mystery” was once used in its most literal sense, to describe a crime – usually a murder – that takes place in a room bolted from the inside, so that there is no way for the killer to have got out, or even to have been there at all: Edgar Allan Poe’s The Murders in the Rue Morgue is usually seen as the first major example of this form. Over time, though, the term has become a more general descriptor for any sort of seemingly impossible crime where “howdunnit” is more important than “whodunit”.

Take Agatha Christie’s widely read classic And Then There Were None (or Ten Little Niggers) – here, the “locked room” is a whole island cut off from the shore, where ten people die one by one, leaving the baffled police with multiple victims and no killer. Another favourite premise involves an open field where footprints can be seen in the snow, or sand, leading up to a crime scene, but none leading away. (One of my very favourite short stories in this vein is Fredric Brown’s “The Laughing Butcher”, about which another time.)

Naturally, plotting and executing such stories with any success requires an author to be highly skilled at the art of misdirection: at strewing red herrings about for us to slip on, using intriguing but ultimately irrelevant details to divert us while crucial information is consigned to the background or falls out of sight.

There are countless examples of such misdirection – almost as many as there are such novels or stories – and it’s fascinating to see how many different tricks the genre’s most prolific and inventive writers have up their sleeve. But one widely used technique is to use the possibility of the supernatural to confuse the reader, so that you’re not sure if what you’re reading is a ghost story – belonging to the realm of fantasy – or a mystery with a plausible, real-world explanation.

Take John Dickson Carr, who wrote so many novels and short stories both under his own name and as “Carter Dickson” that it won’t hurt to give away the denouement of just one of his stories (without naming it). This one centres on a young woman who dies after being savagely blinded – her eyes torn out – even though she is alone in a room with only one entrance and a single barred window set in the wall.

The final explanation lies in a pair of diabolically engineered binoculars which “stab” anyone who puts them to their eyes and tries to bring the lens into focus. Yet, throughout the story, Carr builds atmosphere by creating an almost gothic world of family curses, sooty stone towers, gallant swains and headstrong (or vulnerable) women. There are references to sinister black ravens, which signal death for someone who has transgressed. All this combines to create an effect that could easily have come from one of the great haunted-house tales.

In The Demon of Dartmoor (don’t worry, no spoilers here), Halter does something similar by mining our uncertainty about the nature of the mystery. Part of the trick is this: the multiple murders seem confounding when we look at them as a whole. If an apparently invisible antagonist is responsible for the deaths of three women and one man in the present day, as well as another murder half a century earlier, surely something otherworldly must be afoot. But when you break the crimes down, treat them on individual terms, and allow for the possibility that just one of the witnesses might be mistaken (or is lying) about a specific detail, a different picture emerges.

This is not to say that Halter cheats the reader – he is scrupulous throughout. The method by which Nigel the actor is killed while posing for a photo is clever and plausible, and also so obvious, after it has been explained, that you might want to smack yourself on the head. And we are given one important clue. But to figure out the solution, it is important for the reader to focus on the details of this one incident – including the witnesses’ description of the victim’s body language at the crucial moment – rather than get lost in a tangled forest where we are constantly thinking about invisible men, misty moorlands and ancient spells.

Halter’s prose, at least as one experiences it in translation, is only functional – nothing polished or literary about it – but there are a few clever decisions he makes at the level of sentence-phrasing. Consider the end of the chapter leading up to the actor’s death, after he has jumped up on the window-sill for the picture, for an example of how an author can hoodwink a reader even while playing completely fair. (And I won’t say more.)

What a haunted tree cannot do

If supernatural allusions can be used to give a reader the chills, or create uncertainty about what direction the story is going in, occasionally they can provide a light touch too. In the delightful short story “The Problem of the Old Oak Tree”, written by Edward D Hoch (another astonishingly prolific master of the impossible-mystery form), a country doctor named Sam Hawthorne relates a stumper he became involved with in 1927. During the shooting of one of the first sound films, a stuntman parachuting off a small biplane landed in an oak tree – with a reputation for being haunted – and was then found to have been strangled to death. How could this have happened?

In this case, the oak tree adds colour to the story – it certainly makes a visual picture of the death more striking and vivid – and some humour too. (“Even a haunted tree doesn’t strangle people with a piece of wire!”) But Hoch never encourages us to think that the tree might really have something to do with the killing: the story unfolds like a regular investigation, with little clues and conjectures piling up slowly, until Dr Hawthorne solves the murder.

And then, at the very end, having completed his narrative, he casually informs his listeners that the oak tree was around only for another year or so – it toppled over after struck by lightning. Much the same way that a supernatural-seeming tale might be felled by the thunderbolt of cold reason.

[If this sounds like I am coming down too heavily on the side of rationality, my next piece will centre on a terrific 1949 thriller that contains a practical explanation – and is full of characters who are sceptical and well-educated – but still doesn’t allow its smugly rationalist detective the final word.]