Creative writing: Unlocking the locked-room mystery

It’s fair to say that the locked-room mystery is a format with staying power. Nearly 200 years ago, Edgar Allan Poe’s Murders on the Rue Morgue was published, widely believed to be the first detective story but also the first locked-room mystery. In his tale, he sets out the basic rules of the sub-genre: someone is found dead inside a locked room into which no other person could, it seems, have got in or out. For the next couple of centuries, then, it’s been the job of the fictional detectives – whether professional or otherwise – to discover how such a murder was committed, and by whom.

When I embarked on writing my third book, Freeze, I didn’t initially intend to write that kind a locked-room mystery. But 50,000 words or so into a draft on an entirely different book, I realised that things had gone slightly off the rails. Appealing to my editor, I was met with the suggestion of trying something completely different. What about a locked-room mystery?

But I wanted this book to be something really different. Wouldn’t repurposing such a well-worn structure risk being a bit…. dull? There are only so many methods one can think up (and though it pains me to say it, Poe’s neat reveal of a trained orangutan committing the Rue Morgue murder kind of stretched the suspension of my disbelief). 

Technically, the locked-room format is distinct from the closed-circle mystery, though the two are usually used interchangeably. In the latter, the access to the crime scene is not quite so limited, but there are a small number of possible suspects. But if everyone from Poe to Agatha Christie to Lucy Foley has written variations on the formats, how do you go about making yours fresh?

The first part of the answer is location. In the same way many of the best novels are memorable not because of the complexity of their plots but the uniqueness of their characters, location is key to a distinctive locked-room thriller. And at the time of writing I, along with most of the planet’s population, was hankering for travel, and if I couldn’t go anywhere in real life, a fictional trip would have to do. I wanted somewhere that screamed adventure. And danger too: an environment that would form a strong part of the character of the story, and somewhere that has isolation built-in. Remembering my editor’s advice to think about ‘big nouns’ to make the book unique led neatly to the Arctic. As my friend and fellow writer Dom Nolan said, it made for a locked room thriller in which the room itself could kill you.

The decision to set the story on a boat was borne of three things: necessity, knowledge and malice. Necessity, because the characters needed a base. Keeping them in a single location could have limited the action of the story, so a moving base seemed ideal. Knowledge, because I happen to know boats – I spent many years living aboard barges and therefore have a bone-deep understand of their confined spaces, and the claustrophobia that can build up. Malice, because a boat is just wall-to-wall (or, bulkhead-to-bulkhead) danger. A boat can break down, get lost, sink, catch fire, fill with poisonous gas. The prefect choice.

Because the book was largely planned and written during various stages of lockdown, the usual opportunities for research were harder to come by. Visiting story locations, meeting sources in person, shadowing people at work: all of that was more difficult. So I’d need to rely on my existing pools of experience. Luckily, I hadn’t yet exploited my former job in TV production for the purposes of fiction – so was now the time?

I’d always been fascinated by the disparity between how people behave on-camera and off-camera. From presenters to seasoned interviewees to contributors from the public, the moment red light started blinking, everyone had a persona. Especially me – as an undercover camera operative part of my job was literally to pretend to be someone I wasn’t – an agency worker, a potential customer, a service user – and find ways of recording things without being detected.

Crime novels, and especially psychological thrillers, always have secrets at their hearts: secrets that people will go to extreme lengths to protect. Wouldn’t it be interesting, then, to tell a story through the eyes of two women who’ve spent their professional lives being one person in private and entirely another when the camera’s rolling?

It was from these three bare bones – character, location, structure – the first crystals of Freeze started to form. Using the old adage ‘write what you know’ and wheedling out the most interesting elements of my own personal and professional experiences, I manipulated a tried-and-tested format into something new. Whether I’ve done justice to the wide and illustrious canon of locked-room mysteries, though, is something my readers will have to decide for themselves.

Freeze by Kate Simants is published by Viper, £14.99

Read more on how to create a sense of claustrophobia in your writing with advice from locked-room thriller author Martin griffin