'WHAT are you doing here?" says Harry Potter as Mad-Eye Moody and Nymphadora Tonks burst open the door of his bedroom in the middle of the night.

"Rescuing you, of course, " says Moody.

They're silhouetted in the doorway for a moment, peering into the darkness. Then floodlights click on. The bedroom is a slicedoff segment of a house built with wood and plaster on a soundstage at Leavesden Studios near Watford where David Yates is filming a scene for the $150m Harry Potter And The Order Of The Phoenix, the fifth of seven movies based on JK Rowling's bestselling novels. He peers into a monitor, playing the take over again and again. "Much, much better, " he says, eventually.

"But we need another."

Brendan Gleeson, loosening his great coat and adjusting the protruding 360-degree eye - capable of seeing through walls - that gives Moody his nickname, clumps down the stairway from the bedroom. Technicians begin rearranging the props. Daniel Radcliffe, in pyjamas, climbs out of the bed, and stretches his arms.

If Harry Potter, now in his fifth year at Hogwarts School of Witchcraft and Wizardry, grows up in The Order Of The Phoenix - having his first real kiss and joining in a sort of French resistancestyle underground uprising led by his headmaster Dumbledore, with the support of other Hogwarts pupils and Mad-Eye Moody, against the evil Lord Voldemort - so does 17-year-old Radcliffe.

It's nearly seven years since the Fulham-born son of a literary agent father and casting agent mother became the world's bestknown schoolboy. Like Harry he's lived his childhood in parallel worlds of the everyday and the magical. Tutored on set between takes for the Potter movies, he's managed to get A-grades in his exams. Now he's on a gap year, trying to find himself as an actor, a surprise guest in the TV spoof series Extras and appearing nude as a sexually and spiritually disturbed stable boy in Peter Schaffer's Equus at the Gielgud Theatre.

Whatever about his own future, along with millions of JK Rowling fans he'll soon know Harry Potter's. The Deathly Hallows, the seventh and final novel in the series, is due to be published on 21 July, a week after the world-wide release of The Order Of The Phoenix.

Neither Yates nor producer David Heyman nor anyone else admits to knowing how Rowling plans to wrap up the saga. "Jo is very gnomic about what comes next, " says Yates, best known before this for the award-winning chest." But Daniel Radcliffe has some suspicions. "There was a particular prop in my dressing room - I won't tell you what it is - and David Yates was told to hang on to it because he may need it for the seventh book, " he says.

Radcliffe sees the Harry Potter story "as a loss of innocence rather than a battle between good and evil, although obviously you could compare Voldemort to Hitler and the Nazis and ethnic cleansing.

But for me the main thing is a gradual awakening to the truth about the world. Harry goes from being a 10-year-old boy in a normal world which is very dull, and bad things happen to him, into this wizard world where at first everything is absolutely fantastic and he loves it. After a couple of years he awakens to the fact that bad things are happening, a lot worse than in the normal world."

Radcliffe's film-making experience has followed a similar arc.

"The Goblet of Fire was really fun and charming. A lot of the time it was special effects with these amazing set-pieces. But what's exciting for me as an actor is that now in this one I get to do some really interesting human stuff. I would rather do a great emotional scene with Gary Oldman than I would fight a dragon."

Oldman taught Radcliffe to play bass guitar while they were filming The Goblet of Fire, and they've become friends off-screen. When his character Sirius dies in The Order Of The Phoenix Radcliffe didn't have to feign emotion, although he was given a bereavement counsellor to help him understand what Harry was going through.

"I've never been bereaved, luckily, " he says, and adds, joking, "Maybe I should get a goldfish and kill it."

Kissing Hogwarts classmate Cho Chung - in real life Katie Leung - was more difficult. "I was really nervous because I know Katie, and it's a bid odd suddenly to be so intimate with her. But after five takes it becomes such a clinical process there's nothing exciting about it. I've got ideas about what I'm going to do as an actor and losing every inhibition.

I'm at a stage where I can be pushed further and David Yates is very good at pushing me. He'll come up after a take and tell me, I think you can do better. He's never willing to settle for less. He wants everything to be real and detached."

Although he reads widely - particularly history and religion ("but I'm not religious, it's the philosophy that interests me") - he won't be going to university. "Most people go there to find out what they want to do, and I already have a pretty good idea of that. Besides I'm incredibly easily distracted. If there's something more interesting to pay attention to, then I will always go to that."

David Yates is now ready to shoot the next take. Radcliffe pads away in his slippers and pyjamas.

It's a chance to look over the vast Ministry of Magic set, which is beneath the real-life Ministry of Defence and is imagined as a continuation of the London Underground - if you take the wrong turning you could end up there.

Harry enters it through a telephone booth near Scotland Yard.

It's built to last, like all the lovingly detailed Potter sets. After Deathly Hallows, Leavesden will continue as a shrine for Potter fans, together with a Harry Potter theme park in Orlando, Florida.

"We're expanding the story still more beyond Hogwarts, " says producer David Heyman. "It's something that obviously will continue in the sixth film The Half-Blood Prince and I know continues in the final one The Deathly Hallows, because one of the Harry's last lines of The Half-Blood Prince is, 'I'm not going back here any more.'

So I suspect a lot of The Deathly Hallows will be outside the school.

There's a beginning of the sense that the Muggle world and the magic world are living side by side.

We aren't pulling punches emotionally in this one and we won't in the next two.

"Children resent being patronised. They want films where they're being treated with respect.

So we're pushing the envelope.

We're approaching the stories more and more from Harry's point of view. We're getting deeper into his head."

If only JK Rowling knows for sure what will happen to Harry Potter in The Deathly Hollows it's not for the want of asking as far as 15-year-old Evanna Lynch concerned. "I told her how I think it should end, " says the Termonfeckin schoolgirl described by Rowling as "perfect" for the role of Luna Lovegood, the slightly dotty Hogwarts pupil. "She just nodded and smiled." Evanna has read all the Potter books several times - "I keep going back to my favourite bits" - and as a small girl I wore 'I love Harry Potter' T-shirts. She persuaded her father to bring her over to London for open auditions early last year. "My mum said I hadn't a snowball's chance in hell.

But I was thinking they have to find someone, so why couldn't I have a go. It's kind of like, as Harry says, 'Think of all the great wizards in history and if they can do it why can't you.' I'd been wanting to be Luna since she came into the book. So I just couldn't believe it had actually happened. I like her honesty. She doesn't pretend to anyone. She doesn't worry. She says what she thinks. She makes up her own mind. I like that."

Over 15,000 girls auditioned for Luna. "But truthfully there was only one Luna, " says Heyman.

"Evanna is Luna. She's very selfpossessed. She lives in her own world. She has a wonderful dreamy quality. But she's really got a sense of herself and who she is."

Radcliffe took Evanna under his wing. "He really makes you feel welcome, " she says.

"He doesn't talk down to you."

He helped her get around the confusion of shooting out of sequence - "I had to do my last scene before I did my first one" - and having to keep doing loads takes for every scene. "I found it hard to keep it fresh, " she says. "The words began to sound so boring. You feel like the crew must be so sick of you."

The Order Of The Phoenix and The Half-Blood Prince are her favourite Harry Potter stories, and not just because she plays Luna.

"It's all to do with Dumbledore's army. They're all fighting back. It has a really nice spirit to it. All the magical stuff takes you away from the real world. But the characters are normal. They're all teenagers.

They have the same problems.

They have their faults. So you can understand that as well."

By now David Yates has finally got the take he wants. Brendan Gleeson ambles over. He'll be glad to get the scars off his face. "It doesn't take that long to put on, " he shrugs. "We kind of kept it so the face was recognisable, using the face rather than the prosthetics. They've got it so I can live in the face, trying to maintain the actor in there."

He's spent three months on and off at Leavesden. "It's not full whack. It's good to be able to pop over and back to Dublin. I know pretty much who I'm going to be each day, more than I did in The Goblet Of Fire when I was kind of two people. But Moody is such a daft creation that he can always surprise anybody. So it usually works out a little differently to how I expect."

While not being Moody he's found time to join Colin Farrell in Belgium where they play a couple of inept hit-men in Martin McDonagh's black thriller In Bruges.

Ralph Fiennes is there too - taking a break from being Lord Voldemort - as a crime boss who orders them to lie low for a while, but with disastrous consequences. Later this year Gleeson will juggle The Half-Blood Prince, due for release in November 2008, with playing Winston Churchill in Thaddeus O'Sullivan's Churchill at War.

"I wouldn't miss Harry Potter for the world, " he says. "I'm glad to be a part of it. There's a purity about what is happening here despite the massive scale of it. The fascination with the final episode is driving everybody crazy, and especially me. Moody is in the next book, quite briefly. I think he will feature in the finale, but who knows. Ask JK. I know as little about what's going to happen as anyone else. But I suppose that's life."

'Harry Potter And The Order Of The Phoenix' opens nationwide on 13 July