Are you done?
“Yes, we finished. I promised myself it wouldn’t end on green screen but inevitably it did. The last shot was us jumping through the screen onto a mat.

Were you in bits?
“Not then but afterwards. I’ve never seen Rupert Grint cry before; it was weird. It was like seeing your Dad cry. But now we’re on to new things and I’m looking forward to the future. I’m very excited about The Woman In Black. I think James (Watkins) is great; he’s going to be the next Chris Nolan I think.”

You’re going to have to be scared a lot.
“Yes, but that’s OK; I’m good at scared faces.” [demonstrates his scared face, which is admittedly accomplished]

What was making this double Potter like though?
“It was hard. Before, the producers and directors were very good at taking all the pressure on their shoulders, but this time going into it we were slightly more nervous than we were before, because we didn’t want to screw it up as the last one.

It was a long shoot, near enough 18 months, but a film set is the best place in the world as far as I’m concerned. The first part is a very weird road movie kind of thing. The first part is slower paced, but only compared to the second part. There’s more of an exploration of the relationships between the characters, that’s tested for the first times. And you’re not in Hogwarts, which gives it a very different feel from the other movies.

It’s a road movie, in a weird way, and it’s how the characters function outside those familiar surroundings. The second part starts as a heist movie and then turns into a war. It’s epic. The thing they did on the last day was to play us the trailer, and there was a collective sigh of, “Phew, it’s going to be really good”. This is the first time I’m genuinely excited to see the film. Because it was filmed over such a long period, I’ve genuinely forgotten what we shot early on."

Have you watched the films on DVD?
“I do, but I rarely watch them. I have two friends – just two! – and one wants me to play the Lego Harry potter game with him, and the other wants me to give him an uncensored commentary with them sometime."

So a Potter-thon?
“No! I do get really embarrassed watching the early one. I was talking to Emma on set once on set and saying how bad we were, and we were on mike, and suddenly I heard Mike Newell shout, “You got it because you were both BLOODY ADORABLE”.

Since then it’s been David Yates – has it helped having him all the way?
“I think whoever directed the sixth had to direct the seventh; you needed to ensure that there wouldn’t be a distraction there, of a change in style. I’m thrilled that David did them all, he’s the loveliest man, so quiet and soft-spoken, but he has an incredible vision for plots. He can see the entire film in front of him. He can come up to me when we’re doing scene 328 and reference something we did in scene 8, and I’ve got no memory for those things."

What role do you have your eye on if they remake this in 30 years?
“I don’t! But if I have to, Sirius if they do it in 30 years, and Dumbledore if they do it in 50. But Sirius is the part that everyone wants; Ian Hart had just read the third book on set of the [first] movie, and he was kicking himself that he didn’t get Sirius. But of course I was glad that went to Gary Oldman, because as you all know he's my true love.”

Not Snape?
“I don’t think so, but only because Alan Rickman is so indelibly printed on that role for me and I can’t imagine anyone else doing it.”

Then we saw an action-packed bit of footage, with a few fresh snippets that weren’t in the trailer: six of Harry’s friends turning into Polyjuice Potion doppelgangers to get him safely out of the Dursley’s home; the attack on Fleur and Bill’s wedding reception; Harry and Ron fighting in the tent when they’re on the run and Voldemort heading up a council of Death Eaters at Malfoy Manor. And then lots and lots of intense action, including an extended look at the run through the woods with Death Eaters in close pursuit.

How did you persuade Radcliffe to come onboard?
James: “He read the script, he loved the script, and we met in LA –which is weird since we both live in London – and he loved it. He’s obviously finishing Potter and he’s just looking for new things. He’s a very smart guy, very talented.”