Rowling: I know that Hermione is incredibly recognizable to a lot of readers and yet you don’t see a lot of Hermiones in film or on TV except to be laughed at. I mean that the intense, clever, in some ways not terribly self-aware, girl is rarely the heroine and I really wanted her to be the heroine. She is part of me, although she is not wholly me. I think that is how I might have appeared to people when I was younger, but that is not really how I was inside.

What I will say is that I wrote the Hermione/Ron relationship as a form of wish fulfillment. That’s how it was conceived, really. For reasons that have very little to do with literature and far more to do with me clinging to the plot as I first imagined it, Hermione with Ron.

Rowling: It was a young relationship. I think the attraction itself is plausible but the combative side of it… I’m not sure you could have got over that in an adult relationship, there was too much fundamental incompatibility. I can’t believe we are saying all of this – this is Potter heresy!

In some ways Hermione and Harry are a better fit, and I’ll tell you something very strange. When I wrote Hallows, I felt this quite strongly when I had Hermione and Harry together in the tent! I hadn’t told [Steven] Kloves that and when he wrote the script he felt exactly the same thing at exactly the same point.

Rowling: That is just it, you are so right. All this says something very powerful about the character of Hermione as well. Hermione was the one that stuck with Harry all the way through that last installment, that very last part of the adventure. It wasn’t Ron, which also says something very powerful about Ron. He was injured in a way, in his self-esteem, from the start of the series. He always knew he came second to fourth best, and then he had to make friends with the hero of it all and that’s a hell of a position to be in, eternally overshadowed. So Ron had to act out in that way at some point.

But Hermione’s always there for Harry. I remember you sent me a note after you read Hallows and before you starting shooting, and said something about that, because it was Hermione’s journey as much as Harry’s at the end.