Grammar to hammer: Horror writers use every trick from aliens to zombies. Lynne Truss chose a talking cat

What are the rules for writing a comic-gothic novella? Having been commissioned by the Hammer series to contribute a book, I knuckled down to it last year and produced Cat Out of Hell, in which the mystery of a missing woman is linked to the 85-year history of a talking cat, and there are scary scenes in a variety of locations: a wintry cottage by the sea, an academic library at night, and a car covered in snow. At no point did I consult any books about how to write horror.

Being a long-time fan of the great MR James, and of early gothic novels such as The Monk and Frankenstein, I knew that I wanted to use layers of narration and an innocent protagonist drawn into a story by his natural curiosity. But this was the extent of my conscious plan for the book. Having now just consulted a useful guide entitled Horror Writing 101: How to Write a Horror Novel (by Steve French), I discover that as the source of horror in one’s novel, one can use anything (alphabetically) from an Alien to a Zombie, by way of Creepy Teen, Gargoyle, Possessed Car, and Scarecrow – but it’s too late to learn this now. Mine is about a talking cat, whose name is Roger. In the course of uncovering Roger’s full and frightful story, I found that I fell in love with this astonishing cat, despite all the deaths he had caused and all the hideous evil he had known.

On Steve Clark’s handy list, of course, there is also “Undescribable Horror”. All fans of MR James will know what is meant by this. James was the master of not describing things. A man reaches into a hole and feels something wet and hairy which is indescribably foul to the touch (and I know what you’re thinking: what a case for Uncle Sigmund). Most of the horrible things in James’s ghost stories were, literally, described as indescribable – but it worked, so no one is complaining.

However, what I failed to appreciate in writing my own comic-gothic novel was that I would re-define the phrase “undescribable horror” as a great failing in a book rather than a great triumph. Because in the modern world of book promotion, it’s quite important to be able to sum up your book, and I simply can’t. “It’s sort-of indescribable,” I say, weakly, to radio interviewers. “Did I say it was about a missing woman and a talking cat? I did? Oh dear. So I did mention the cat? And you actually want me to say more than that?”

I think I used to be rather envious of people who couldn’t talk about their novels. “If I said anything more I would give too much away,” they would say, airily; and I would think, “How very cool and sophisticated.” However, now that I have written my indescribable book of comic horror, I feel mainly like an idiot. “OK, so it’s about a cat, a talking cat,” I say carefully (while my mind frantically scans the words for any ruinous indiscretion). “There’s a missing woman, and a folder of documents and photographs, and an interview with the cat, but I can’t really tell you what’s in the documents, you see. Or what’s in the photographs, not even the one with the dead man hanging from a tree. Or anything that the cat says. Or why Roger pees on the iPhone. Or how the library comes into it. Or the car. Or what happened at Harville Manor to those poor, poor, defenceless kittens in the years after the war.” In advance of publication, I warned my sympathetic publicist that journalists would probably want to talk to me about apostrophes (groan) – and I said I’d be reluctant to do this. But I have changed my tune completely, now that reality has hit home. If it means not struggling to summarise a plot that consists entirely of spoilable surprises, I am thrilled and relieved to talk about any punctuation mark whatsoever. I will even talk about … the ellipsis.

Suddenly one can see why non-fiction is enjoying such a heyday. Non-fiction is just such a doddle to talk about. You can even read aloud quite entertainingly from non-fiction works without having to set the scene first – one of the most deadly things a novelist’s audience ever has to sit through. I have watched this many times: the fiction author opening his book about half-way through (where it would fall open naturally). He sips water, coughs, lovingly smooths the page, and then begins to explain. “You need to know that Henry has left Gabriella, and that Orlando isn’t all he says he is, but ha ha, I’ll say no more about that. They moved from Sherborne, but Chipping Norton isn’t an improvement. Ha ha ha, for obvious reasons. Oh, and Vanessa isn’t any longer friends with Gabriella …” And so it goes on, with the audience politely nodding as if making mental notes, and all the while thinking, “Who cares about these people, for God’s sake? You made them up!”

The good news from the Steve French list is that “Talking Cat” isn’t on it, so at least I have bucked convention there. I did feel I was writing something that hadn’t been written before. But oh dear, I should have remembered to write a special passage in it that can be lifted out for readings, and I also should have guarded against this shameful indescribability thing. The irony is that this book of mine is very highly structured – it is taut and plotty, above all. But when your book is all about getting to the bottom of a story, the starting position seems an inadequate thing to describe; and everything else is either out of bounds, or needs too much explanation. Damn, If only someone had told me not to write a comic-gothic novella involving a talking cat and a missing woman and a well-meaning bereaved former librarian, all this expositional discomfort might just have been avoided.

Extract: Cat Out Of Hell by Lynne Truss (Hammer, £9.99)

“Apparently it’s all bollocks about cats bringing us mice and birds because they believe in some childish way that we’re their big upright parents who will pat them on the back or something. They do it for only one reason: because birds and mice are their limit, but they think they’ll get their big evil powers back if they only do enough killing.”

Cat Out of Hell by Lynne Truss is published by Hammer Arrow on 6 March in hardback at £9.99