Daniel Radcliffe, Emma Watson and Rupert Grint, the three leads at the heart of the Harry Potter series, return in the third instalment, The Prisoner Of Azkaban.

What was it like seeing your faces on the big screen?

RG: Yeah, it's really weird seeing yourself on the big screen - it's quite scary - but I've sort of got used to it now, it's quite cool.

DR: I've never really liked watching myself that much. I saw the film with some of my friends and I was sitting in the front row of the cinema, and the last frame of the film is one of my face, and it looked like I was about to eat the front row of the audience. It's kind of scary and a bit surreal, but I think we've all gotten used to it now.

How different was it working with Alfonso Cuarón compared to Chris Columbus?

DR: Everything we learned with Chris over two years - which was a lot - we now get a chance to put it into practice with another director. That was a challenge in itself, because we had to get used to someone else's style, but it has helped us a lot to evolve or develop just making the transition.

RG: Yeah, it was a bit weird when we found out there was going to be a new director - we'd gotten really close to Chris, I was really used to him. But Alfonso was wicked, we had a really good time.

This time around we see you in jeans, more ordinary clothes. Were you relieved to be out of the school uniforms?

EW: I think it made things more normal, more comfortable. It made it easier to do the stunts as well, and it lets you see a different side to all of the characters. Plus, we're teenagers now, and I think that that has more of an influence on it. It feels more personal when you are in your own clothes.

DR: Also, more of the story this time takes place in the holidays between terms, so it was quite natural - I don't think that any child anywhere in the world actually wants to wear their school uniform. Apart from Hermione...

RG: Unfortunately Ron still gets his hand-me-down Weasley sweaters, so I never got to experience the normal clothes.

How do you see your lives beyond the Harry Potter movies?

EW: I love performing; I love acting; I love singing; I love dancing. There are so many different aspects of the film world that hopefully I will end up in some area of it. Maybe on the stage, I don't know. Whatever gets thrown at me, really.

DR: I've got loads of other things that I'm interested in, like music, but I do love acting, and it is something that I want to go on and do. I suppose we'll have to see what happens.

RG: I'd like to carry on doing films - that would be pretty cool. But then, when I was a kid I wanted to be an ice cream man! That seemed like the ideal job for me.

What's it like being the cleverest witch, and do you think that girls are cleverer than boys in real life anyway?

EW: Oh, definitely! I love playing Hermione, she is so charismatic. She's a fantastic role to play, especially in this third one. It's my favourite book, my favourite script. She's taken two films of people being rude to her, being nasty to her, and either pretending that she didn't hear or just saying "forget about it". But in this one it's a real turning point for her because she says "That's it, I'm not taking this any more!" She punches Malfoy, she storms out on teachers. She's rock and roll, she's girl power, she's feisty in this one.

Are you enjoying making these films and everything that goes with them as much as you first did. And secondly, if you could influence the way your characters ended up at the end of this adventure, how would you have them end?

DR. My favourite part of the whole process, including the interviews, the premieres, whatever, is always the work, actually making the films. People say it's work, but it's not really work, is it? I really enjoy it. It's challenging for me, but it's fun, I really enjoy doing it.

I'm going to be really unpopular for saying this about Harry Potter but I always have had this suspicion, that with everything going on in his life, I think he might die. I have a theory - because Harry and Voldemort have got the same core in them: you see that connection between them in the fourth book - I think that the only way that Voldemort can die is if Harry dies as well. I'll probably turn out to be completely and utterly wrong.

EW: I feel quite close to Hermione - I feel very protective of her when I read the books, so I hope she ends up doing something that she loves, I hope she ends up being happy.

With Ron?

EW: Maybe!? Maybe... if that makes her happy...

RG: I'd like Ron to turn a bit evil. That'd be cool - I just want to play an evil person.

Is there anything about filming you don't like?

RG: I had a rat in this film. When we were in Scotland he peed on me. That wasn't really nice.

Alfonso asked you to write an essay about your characters' evolution. What did you write?

DR: It was a long time ago - I've completely forgotten. All I remember is that we ended up being freakishly like our characters. Emma hates me to bring this up, but I wrote one page of A4 about Harry, and Emma, well, Emma wrote about 20 pages.

EW: No! It gets more and more every time. It was ten, then 12, then 16, now 20? Come on! I have big handwriting, and I leave big spaces, OK?

RG: I forgot to do it... [laughter]

David Heyman [the producer] has said that you might end up too old for the parts one day. Would you mind, or would you want to get on with your lives and do other films?

DR: Whatever happens happens. I love doing the films, but I am interested in going on to do other films at some point. When that will be, I don't know.. Each one takes about a year to film, then about six months after that until it comes out, so there's a while until I have to think about doing a fifth one yet. I'm not going to lie and say it'd be completely easy, and that I'd be happy someone else playing the part - it would be extremely strange having played it for what would be four films. If it happened it would be something I'd have to get used to.

Also, people do play people younger than they are in real life. I'm going to be 15 in a couple of months, and Harry is 14 now, so I don't think it would make that much difference, really.

RG: I'd like to go on. I really do enjoy Ron, it's a really good experience.

EW: We only started the fourth one two weeks ago. Every film takes a year to do, and these are big projects, and I think it's hard for all three of us to look anywhere beyond that. I'm not sure yet.

What does growing up to be an adult mean to you?

DR: I suppose I won't actually know until I grow up. I don't know.

RG: My voice has got a bit deeper. I've got a bit taller. That's all I really know so far.

EW: I'm having a pretty good time as a teenager at the moment. It's an interesting age. It's a time of discovery, of making mistakes, and learning from them. I intend to enjoy it.

Were you intimidated with working with such an amazing cast?

DR: Well, I hope Gary [Oldman] doesn't mind me saying this, but since I started acting I have always been a really huge fan of his. I've watched loads of his films and think that he is just the most fantastic, fantastic actor, so for me to be working with him is absolutely a huge honour and a privilege. To be working with Gary, David Thewlis, Timothy Spall and Alan Rickman in the same room was quite intimidating - not because they were intimidating us, just because they are such fantastic actors. Seeing them together was just fantastic to watch.

RG: It's a bit scary when you first get to meet them but they are really just down to earth, easy to talk to people. That is one of the reasons I really enjoy acting - you get to meet all these cool people.

EW: The last scene, which had Alan Rickman, Timothy Spall, Gary Oldman and David Thewlis all in the same room, was a bit overwhelming, but it was great because it really challenged me. Even if it wasn't personal advice, just watching them work was a huge help in terms of helping us mature as actors. I was so pleased to be working with Emma Thompson. She's done a great job with Trelawney - she's absolutely hilarious.

How do you feel about being big movie stars, and what do you do with all the money you earn?

DR: It's in a bank, I don't really use it. You know, I'm 14, I don't really have a major need for it yet. I buy a lot of CDs, but that's it really. And the movie star thing: it sounds like a big cliché, but it doesn't really matter to me that much. I really like doing the work, and that is what matters the most.

EW: My money is in a bank until I'm like 25, 18, I don't know. It's weird, but I don't really feel like a movie star - I feel like a movie star for like two, three days of the year, but the rest of the time, I just go back to being, well, normal.

RG: Yeah, it's a bit weird, but you sort of get used to it. The money is nice to have, but it's not that important. That said, I do spend it. I got one of those cool little quad bikes - yeah, stuff like that.

Are you happy to be associated with Harry Potter for the rest of your career?

DR: That's a cheerful thought... The stupidest thing I could possibly do would be to be angry at being thought of as Harry Potter, because it has given me so many amazing opportunities. Hopefully I'll be able to go onto other things, play different characters, and hopefully people will like it. Ideally, the first thing I do after Harry Potter will be different from the character of Harry, but the ideal part for every actor is different from the last part he did, so we'll see what happens.

How has doing the Potter movies over the last four years influenced the way you've grown up?

DR: I think we're maturing the same way that any other teenager goes from 13 to 14. I don't think there's that much difference. Obviously we are on a film set a lot of the time, but I don't think we've lost anything from that. I'm having a great time, and I don't think that it is going to hurt me in the long run or anything.

Emma, have you lost your youth?

EW: I haven't lost my youth! I've known Rupert and Dan since the beginning of this, and I think that they are exactly the same as when we started. I hope that I am too.

Rupert, how is life between the movies? Fairly normal?

Pretty normal. Life is the same as it was before, but I just get recognised sometimes, which is really hard to get used to. Apart from that, I've missed a lot of school, which has been a bonus...