Matt Haig's The Radleys depicts a British family of "abstaining" vampires thrown into crisis after the teenage daughter discovers her "overwhelming blood thirst."

Were you influenced by Boo Radley of Harper Lee's To Kill a Mockingbird?

Yes, Boo, pale-faced, misunderstood suburban outsider, was definitely my inspiration, though I later discovered Radley means "of the red meadow," which can have vampire connotations.

What aroused your interest in vampires?

Vampires are, quite simply, the greatest symbol of forbidden desires and selfish will the human imagination has yet conjured. I find the vampire myth fascinating in all its guises, from Byron and Stoker through '80s guilty pleasures like The Lost Boys to the melodramatic magnificence of the current True Blood. I have always enjoyed vampire stuff without ever having been a full vampire geek. I suppose I love the idea of blood thirst because it can say so much about us, not simply about addiction but about all those desires that can tear a family apart.

Didn't this book originate as a script?

The screenplay and the novel were written side by side, although it is true that the germ of the idea was originally for the screen. People, certainly in the U.K., look down on screenwriting as an art form, but I love the discipline of it. Next to the bagginess of novel writing, it almost feels like a martial art. I think the novel ended up better than it would have done if I hadn't gone through that process in terms of structure and characterization. Alfonso Cuaron is attached to produce my screenplay, and now has BBC Films on board, too, so it's up and running.

If your children didn't know they were vampires, when would you break the news?

I'd wait till they were the right age and break it to them gently, while watching The Lost Boys. The Radley parents did the wrong thing for the right reasons. Parents can only do what they think is best, with the experience they have. The learning curve for every parent is that there's a limit to how much they can shield children from. This applies double for vampires! What happens when our instincts get in the way of our good intentions? And what if our good intentions end up doing more harm than good?

Will there be a sequel?

Yes, The Radleys was always intended to be an ongoing story, so there will be sequels and possibly a prequel starring Lord Byron.

You once said, "Life is the biggest black comedy there is." What is death?

The punch line.