Goodbye Van Helsing. Hello Sherlock Holmes.

Since it's Halloween it only seems right we talk horror. Back when I was an excessively-kohl'd teenaged Goth horror was all I read, the melodramatic Victorian classics and splatter-heavy 20th century masters, so when I came to start writing that was the genre I went for and it was only a chance comment by an early reader, who suggested my style was more suited to crime, which diverted me away from it.

The switch was surprisingly painless, after all what's horror but crime with a supernatural agent?

Poltergeists become stalkers, succubi evolve into femme fatales, and as a template for rampaging madmen with daddy-issues you don't have to look much further than Frankenstein's monster. The timing of this change was significant as well I think. Once you're too old to believe in ghosts and vampires you're beginning to see the real horror in the world and, as a writer, this is far more powerful material to terrify your readers with.

Mark Edwards originally conceived his bestselling psychological thriller The Magpies as a horror, but without the supernatural elements,  "Because I wanted to write a horror novel in which the ‘monsters’ are ordinary people. When I came to publish it I decided to market it as a psychological thriller for commercial reasons. However, the narrative arc of The Magpies is more like a horror novel, because in horror, the worst thing you can imagine happening is what actually happens. There’s no escape, no neat resolution."

For Steve Mosby, another writer who started out in horror, the genres have much in common, "But the fundamental differences are intent – horror sets out to disturb and scare, whereas that’s often more a side-effect in crime – and resolution. Crime tends to restore order to chaos, whereas horror has every right to leave you there. In those terms, I use the furniture of crime, but still lean more towards horror for the latter two. I want an emotional, visceral reaction from a reader far more than I want them to enjoy solving a puzzle." 

When horror is in your reading DNA it's tough to shake off as a writer. The first couple of books I wrote incorporated elements of it but they gradually faded out as I focused more on 'ordinary monsters' and realised how disturbing the threat from across the street could be.

It was that urge which prompted serving police officer and crime writer Col Bury - who sees his fair share of horrific things on the day job - to move away from horror too, with his collection, The Cops of Manchester. "It’s because horror can be far-fetched and, as we mature, we strive for more realism."

While ex-cop and former scriptwriter on The Bill Paul Finch started out as horror writer but says, "I had police procedural in my blood. I'd always wanted to return to that form in print, but now flavouring it with the terror, violence and darkness that I'd been experimenting with as a horror writer." The shift has proved enormously successful and his novel Stalkers gives tangible form to those old tales of something watching and waiting in the dark, only now they're 'Nice Guys.'

Is crime then just a strand of horror? Same impulse, different costume?

We grow up, we still need monsters, but we want them to reflect the world around us, and now the creepy forest has been cut down and all the spooky old mansions are carved up into flats, where are we going to go for them? The hoary old tropes are rich for reimagining, allowing the author to wink at the reader on one page then scare the hell out of them on the next.

Gerard Brennan's novella Wee Rockets, about a group of feral youths on a Belfast housing estate was written as a horror, until his reading group pointed out that it was actually crime. But what are those kids but a gang of malicious imps wreaking havoc with impunity?

The classic haunted house novel gets a makeover in Mo Hayder's latest, Poppet, as she throws her detective Jack Caffrey into a high security psychiatric hospital where a series of violent incidents are filtered through the troubled mind of the patients, making for an occasionally surreal and deeply disturbing read, which would have delighted the original forms Victorian fans. And sent them for the smelling salts.

Think of all the psychological thrillers which centre around stolen children, two hundred years ago they would have been spirited away by fairies, now the motives are darker, less opaque, but still play on the same deep-rooted fears. And readers can't get enough of them, because those fears will never go away.

The stories at the heart of both genres are essentially the same, ancient, campfire narratives of good versus evil, except now good is more interesting because it's never absolute and evil is stripped of its religious underpinnings and measured on the DSM-V scale, creating so many more intriguing deviations.