The crowds for horror supremo Darren Shan’s signing are already forming outside East Kilbride’s Waterstones, clutching their books like talismans. Irish author Shan has sold 18 million books worldwide, had a Hollywood movie made of his work and is credited with getting the most recalcitrant of boys to read. Yet unless you’re a teenager or have kids of the right age, the chances are you’ve never even heard of him.

Sitting in a nearby Starbucks in a black hoodie emblazoned with the title of the second of his sagas ‘The Demonata’, the 38-year-old says that’s just how he likes it. “Children’s books are always in the shadows and horror books are in the shadows. So as a horror writer of children’s books, I’ve passed under the radar. I love that.”

Meanwhile, among Shan’s rabid fans, known as the Shansters, the thirst is high for his latest bloody tale. Birth of a Killer returns to Larten Crepsley – one of the vampire stars of Shan’s breakthrough hit Cirque du Freak, which began The Saga of Darren Shan and was afterwards made into a movie starring John C. Reilly and Salma Hayek. The epic new Saga of Larten Crepsley promises to lift the coffin lid on one of the most mysterious figures in that hit series.

“I had no plans to come back to Mr Crepsley,” says Shan, adding that his Japanese publishers had tried to make him do just that years ago. “For a long time I ignored him, but I got to a point that I had so many ideas that it was like voices clamouring in my head, I had to do it.”

Shan promises that he has not let up on the gore for Crepsley’s story, which follows the vampire from his poverty-stricken human childhood all the way through his 200 years as one of the walking dead. Though parents and teachers often ask whether he worries about scaring children, he regards their concerns as ridiculous.

“I hope they will be terrified, because that’s the whole point!” he exclaims. “If you read a comedy book, you want to laugh. If you read a horror book you want to be scared. Children will find their own reading level. If they’re nervous they’re not going to read one of my books. It’s obvious from the cover what it’s about, you’re not going to stumble into one of my books thinking it’s a romance.”

Listen to some now and you’d be forgiven for thinking that vampires are all about the romance. However, this fan of Nosferatu, Dracula and Salem’s Lot has no time for Twilight. In fact, his greatest-ever standing ovation happened at a recent signing in Perth when he announced that the movie was rubbish. “I think every show I do now I’m going to end with ‘I hate Twilight’,” he laughs, “then I’ll ride out on a wave of applause.”