The producer for the Harry Potter series explains omitting funerals and battles from Half-Blood Prince and maps out Harry's journey in the seventh and eighth movies.

A: What I like about David is that in State of Play he's able to handle politics with a small "p," and make politics entertaining. In the fifth film, we see that the world is becoming more political -- we're on the brink of war, there's infighting within the ministry -- and I wanted that to be present but in an entertaining way. He's a great director of actors, and clearly as can be seen from Half-Blood Prince, which is so different than the last, he has so many strings to his bow.

Q: The final showdown in Half-Blood Prince was all but omitted from the movie. Why?

A: We've got a big battle coming up in Seven, and we wanted to leave some gun powder in the keg. But also, the battle doesn't really lead to any resolution -- it ends up with the bad guys getting away. If we'd had the battle, there would be a greater distance between the death of Dumbledore and the emotional impact. And I think that we tried to get to the emotional elements of that as quickly as we could. We also cut out the funeral, which was one of my favorite moments in the book. But again, what we felt was that if we had the scene in the courtyard when Harry comes back to the body, and then a funeral, the grieving would go on for too long.

Q: You were reluctant to split The Deathly Hallows into two movies. What turned you around?

A: When [screenwriter] Steve [Kloves] started the process of adaptation, it became incredibly clear that we couldn't fit everything in using our principle to tell the story from Harry's point of view. If we did that, and if we were to resolve the things that had to be resolved over the course of this story, it may be a 4, 4½ hour film. And I'm not sure I or our audience would have enjoyed that. So I think the first film is very much a road movie: Harry, Ron and Hermione are on the run. And the second film is more operatic and obviously has this great, massive battle at the end.

Q: You produced I Am Legend. What's the difference between adapting classic scifi and this fantasy series, which has become a worldwide phenomenon?

A: I would say the fundamental difference between the two is that Potter's success and the voraciousness of its fans is more immediate and expansive than the "scifi cult" following of I Am Legend. I love that novel. To me, that's one of the great pieces of scifi literature. But the experience of adaptation is very different. What's similar is what you want to capture in them -- you can't be literally faithful to the book. Ultimately the film medium is different than the literary medium, and what you really need to do is capture the spirit. I think Steve Kloves has done the most incredible job embodying Jo Rowling's voice, and I think I Am Legend has some of that too. It's different from the book, but I think there's an awful lot that captures that spirit.