Poirot, ITV

If there was ever a genre of fiction that’s kept at the very height of fashion, it’s the whodunnit. Scout the shelves of any bookshop, scan the listings of the TV schedules: from the timeless classics of Dorothy Sayers to the latest tributes by J. K. Rowling, the modern revival of Sherlock to period adaptations of Poirot, our long-held appetite for the murder mystery verges on insatiable addiction. We often yearn back to a ‘Golden Age of Detective Fiction’, but the truth is we’re still basking within it – so how has this genre achieved such a central status?

Indeed, the detective story has become such a staple narrative format, it’s almost inconceivable that it was invented less than two centuries ago. While some credit Edgar Allen Poe’s The Murders of Rue Morgue (1841) as the first model of the genre, it is Wilkie Collins’ The Moonstone (1868) which pioneered the classic components we reguarly recycle today: an English country house, a closed circle of suspects, a locked-room murder, an amateur detective and the unmasking of the least likely suspect. The familiarity of these components is crucial to its appeal – readers knows that the crime will be solved, the perpetrator brought to justice – but it is precisely the predictability of this structure which proves so inexplicably gripping. In fact, according to screenwriter Anthony Horowitz, every murder mystery is underpinned by a formula quite literally as easy as A+B=C: A is a murderer, B is his motive, and C is his resulting victim.

No genre of reading could possibly follow a more basic pattern, and yet arguably none has spawned such an eclectic and experimental variety of works. It is perhaps this juxtaposition between the simplicity of the format against its potential for complex insights that has put the intellectual value of the murder mystery under scrutiny. I remember being corrected at school for referring to Agatha Christie as one of my favourite ‘literary authors’; ‘fiction writer’ was deemed a more appropriate label, and in an unfairly derogatory sense (let alone for an author outsold only by Shakespeare and the Bible). Ironically it was my enjoyment of Christie’s novels that introduced me to the world of unreliable narrators, anti-heros and narrative voice, and ultimately towards a degree in English Literature, where the strong cultural and literary significance of the detective novel became so apparent.

The Moonstone, BBC

Rather akin to the popularity of television soaps in modern times, the Victorian era saw the novel gather momentum as a powerful vehicle for social analysis. As writers such as Dickens and Gaskell began to scrutinise the fabric of established hierarchies and traditional values, plots began to focus on crime as a way of interrogating contemporary social changes. The serialisation of novels simultaneously placed a new importance on cliffhangers to ensure that Victorian readers remained fully captivated. The gradual exposure of secrets and mysteries became a key component of story-telling, and this newly-developed ‘sensation’ genre quickly paved the way for the whodunnit novel.

Victorian enthusiasts will note that most novels from the period have a murder mystery embedded within a deeper social critique. It was the authors from the so-called Golden Age of the 1920s who are responsible for refining the genre into a sophisticated form of its own. Far from dragging the whodunnit into the low-brow depths of ‘popular fiction’, however, the novels from this period onward still offer a solid if implicit social commentary. Indeed, the crime novel constitutes two integral facets: it dismantles the stability of society, and subsequently reappraises and repairs it. It thrills us by opening the lid on contemporary societal ills and, as a narrative of moral reassurance, closes the lid back down on them.

Broadchurch, ITV

Perhaps more than other genre of fiction, therefore, the continual reinvention of the detective story is powerfully indicative of its prevailing contextual values. It is no coincidence that in Charles Dickens’ Bleak House (1853), the identity of the murderer is inevitably exposed as the untrustworthy French foreigner; Broadchurch (2013), ITV’s enormously successful eight-part whodunnit, unmasks a suppressed paedophile as the killer of a young schoolboy. The detective figure in Mary Elizabeth Braddon’s Lady Audley’s Secret (1862) is the epitomy of Victorian respectability; two centuries later, ITV’s Vera is a flawed alcoholic battling personal demons, the archetypal anti-hero of our times. Even the focus of the crime has morphed from the logical consideration of ‘who?’ to the typically modern, psychological emphasis on ‘why?’

Vera, ITV

This ever-evolving, ever-relevant and ever-surprising potential of the whodunnit goes far to explain our fascination with it. The genre offers us a timelessly engaging puzzle: by zooming in on a small spectrum of suspects and a single crime, the reader is lured into a compelling microcosm of contemporary society and its accompanying complications. We are invited to ponder, doubt and interrogate the ‘problem’ of the novel in a way that few other forms of literature allow. Moreover, by nature of the narrative structure, we are in a constant state of suspension, propelled towards an answer in the form of social restoration.

The ‘old-fashioned whodunnit’ is not old-fashioned at all, and seldom just a ‘whodunnit’. Under the guise of a leisurely read, the genre has proven itself as a tried and tested format of profound literary and cultural value. Its social function, its potential for ingenuinity and, most importantly, its unashmed ability to captivate, are all limitless. As our ultimate authority Mr. Holmes would tell us, ‘There’s the scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, and isolate it, and expose it’ – and long may we expect that thread to run.