Daniel Radcliffe: Okay, so I thought, to begin at the beginning, how involved were you in the casting process and how much do I have to thank you? Do you remember working with Chris?

JK Rowling: I was involved. Not to the extent that I was sitting in on auditions, but they were keeping me really fully informed. As you know, we found Rupert and Emma and they were perfect and that was a done deal. But we still couldn’t find you. Well, you say how you were found because it was amazing, really.

Dan: Well, it was a bizarre kind of moment. Originally what had happened was that David Heyman, the producer, knew my dad because my dad had been a literary agent, and my dad had worked with David’s mum. So David asked my dad if I would audition. And the original deal we’d heard was going to be to do six films and it was going to be done in America.

Jo: It was going to be done in America? No one ever told me that.

Dan: Well, maybe that’s why it changed because you probably put your foot down at some point, or they just went, “ Jo won’t agree to that.”

Jo: Yeah, they know me quite well.

Dan: Which is good, to be honest. That would not have been good. But I’m not somebody who particularly believes in fate and destiny and all those things, but my parents do. So the final straw was the fact that I went to the theatre to see a production of “Stones in His Pockets” and David Heyman and Steve Kloves, who adapted all but one of the books, happened to be sitting in the row in front.

Jo: Can you believe it?

Dan: I know, and I sat there the entire time thinking, “Why is that man …

Jo: “… staring at me? This is very creepy?”

Dan: It was very creepy.

Jo: “I need to phone someone.”

Dan: It was very odd. And I remember at the interval my mum and my dad both looking quite intense about something. But, you know, as a kid that you’re being purposely kept out of the loop for your own good kind of thing. I remember we went up the stairs and out the theatre and then hid behind a pillar. I seem to remember some absurd notion that David Heyman and Steve Kloves were going to chase after us.

Jo: “We’re going to attack. And make you be a child actor.”

Dan: Then there was some debate as to whether we would go back in for the second half, but I was really enjoying the play.

Jo: Really? They were that …?

Dan: Yeah, and so we went back in. And then the next day my mum and dad went, “Oh, well maybe it is the gods trying to tell us something.

Jo: But there were a lot of strange coincidences.

Dan: There were.

Jo: And then they called me and said, “We think we’ve found him.” And then the first time I ever saw you was on screen in my sitting room at home.

Dan: Really?

Jo: Yeah, they sent me a video of you. The curious thing is – and I’m like you, I don’t believe in fate and destiny …

Dan: Which is interesting because it comes up so much in the books.

Jo: Yeah, absolutely. I think you make your own. So I saw you on that audition tape and I don’t think I’ve ever really told you that I found it incredibly moving.

Dan: Thank you so much.

Jo: It was incredibly moving. At that point, I didn’t have a son. I phoned David up and I said, “He’s great. He’s fantastic.” And I did say to David it was like watching my son onscreen. Because, after all, Harry feels like this ghostly son I’ve had in my life.