I see you brought back a potential series regular, billionaire David Nabbitt, for this book. What was our interest in the character, and do you think he should have been explored further on TV?

Dan Jolley: I found myself enjoying writing David almost more than any of the other characters - in part, I guess, because he's such a fish out of water, but he loves it.

He's aware of the underlying supernatural goings-on in the world, and he's had some experience with it, but he's still at the stage of saying, "Oh, wow, look at that!" And I think that's probably the stage I would spend a lot of time in myself, were I in his position.

David represents geekdom really well; he's a sci-fi/fantasy fan who's realised he actually can be a part of the story, and even though it scares him witless, he still finds it supremely cool. On the show I think he's been woefully underused. Sure, his social skills are non-existent, but his heart's in the right place, and he's a very valuable resource, both in giving advice and providing financial support if necessary.