J.K. Rowling: This was wonderful, and I got to work with and form friendships with some immensely talented people. And I must say - and I'm very emotional saying this - one of the things that I have been proudest of is going down to Leavesden and looking at all these people, with all these jobs - hundreds and hundreds of people, and occasionally I've looked and thought, "Oh, my God, these people have jobs because I had an idea on a train once." Overall, the experience of the films for the initial writer has been outstanding.

There's a huge amount of action in this; it's a war movie, actually. Part 1 is a road movie; Part 2's a war movie, with everything that implies. It's incredibly sad in places, it's very exciting in places, and I feel that all of the major characters have sublime moments. What I always, in mentally refer to as the big seven - which is Harry, Ron, Hermione, Ginny, Neville, Luna, and Draco - so, for me, the big seven, all of them have fantastic moments in this final, cathartic battle. You can probably tell I love it, I think it's probably the best.

A huge theme throughout the seven books and the films, Dumbledore expressed it right at the beginning of the series, at the end of Philosopher's Stone when Harry says, "He's not gone," and Dumbledore says, "No, but if the next person fights him, and the next person fights him, we can keep him down. And that goes to the heart, really, of the series, which is the question, "Why fight?" Why fight? We accept the inevitability of evil in the world, and we accept that things can't always be fair. We accept that things will never be perfect. Why fight, why fight? And that's the question that all of the characters answer in their different ways; some characters say, "I'm not fighting, I have to accept the inevitable," and other characters say, "I will fight till I die, to make the world a better place, to save a friend." And I suppose that's what the final battle is about.

They do it perfectly in the film, that was a place I where I was really glad they were faithful to the book, because Snape's journey is so important, and such a lyncnpin of the books, and it can't function without Snape, but he's much more than a conduit for information. He's an interesting character, and he is - I think all of my characters, without exception, Harry included, are flawed - and I don't think we have a wholly good or wholly bad person with the exception of Voldemort. He is wholly bad; there is no redemption there.

Walking into the Great Hall in 2000, maybe, was it? Around 2000 was the first time I did that, it was amazing, it was wonderful - it was exactly as I imagined it. Chris Columbus and Stuart Craig, I talked to them about how they saw, and they had done such a magnificent job. I actually didn't want to see it destroyed, and seeing it destroyed on film was awful, horrible. I think everyone would feel that, all the fans, all the way through. You get such a sense of how serious the situation is, just how destruction this war has become.

It's a very intense feeling I have for them, because they have literally lived in my world, and they've done it such honour, and because they have been so magnificent in the way they have grown up and played their parts, and it just so happens - which is the most important thing of all - that they are three fantastic people. You'd go a long way to find three brighter, nicer, more grounded people than Dan, Rupert, and Emma.

I always had a feeling that Rupert [Grint] just knew - I always had the feeling, I may be wrong, if you interview Rupert, he might say different, but my strong feeling is that he got Ron inside and out, and I don't know that he needed anyone to tell him. Dan is one of the most inquiring minds I have ever met. Dan wants to know, he wants to understand, and he does, and he makes sure he masters it, and he does it. And Emma, she just - there's sufficient overlap between Emma and Hermione that she's just the poster girl for clever girls, isn't she? She was wonderful, but she could do so much more than just be the nerd, and particularly in the last film she showed that, when she and Dan are playing these two characters are alone. The depth of emotion Emma came up with there was extraordinary.