The end is nigh for Harry Potter, with The Deathly Hallows - the final act of the most lucrative book-to-film franchise in history - set to descend upon us.

But, as you'd expect from the previous six supernatural instalments, J.K. Rowling's Hogwarts' saga unfolds as spectacularly as it started, with good and bad clashing in a deadly duel.

In order to capture the sheer magnitude of the upheavals since Dumbledore's death in The Half-Blood Prince, including Lord Voldemort's rise to power and sinister domination of The Ministry of Magic, Rowling's epic has been split into two films.

The first follows Harry on his quest, along with his sidekicks, Hermione and Ron, to destroy the remaining horcruxes - the relics that Voldemort has secretly stashed remnants of his soul in.

The second culminates in the cataclysmic, do-or-die battle between Harry and Voldemort to finally end his reign of terror.

"We were all aware that this great juggernaut was reaching the end of its journey, so we wanted to give it and the characters the proper send-off they deserved," says producer David Heyman, describing the rationale for the split.

"The only way to do that and preserve the integrity of the work was, we felt, to have two parts because Deathly Hallows is so rich, the story so dense and there's so much that is resolved."

Daniel Radcliffe had campaigned from the start to break the story into two movies. Unlike the earlier books, which had secondary plot lines that could be omitted, Deathly Hallows had few details to drop, Radcliffe says.

"It's just the three of them on the road, and that's what you're focusing on, that's where everything happens. So there's very little you can actually cut without changing the story," he says.

"There was no way you could do justice to the book and really capture the story in one film, unless you made that film six hours [long].

"And while I know there are some Potter fans who would be quite happy to have a six-hour Harry Potter film, we do want to make films not just for the huge fans of the books, but also for the other people, regular cinema-goers, who perhaps haven't read them. So it was essential to make it palatable for sort of everyone, while also remaining true to the book, and to do that, you have to make it into two films."

Similarly, to ensure cinematic continuity, director David Yates - who previously helmed Half-Blood Prince and Order of the Phoenix - was re-enlisted for both parts of Deathly Hallows. That decision became a life-saver during filming, says Matt Lewis, who plays Neville Longbottom.

"Not only was it a really long shoot, it was also really tricky because we didn't film them back to back," he reveals. "We shot them simultaneously, like Lord of the Rings, so it got really confusing. If we didn't have such a good crew and David directing us, it could have got completely out of control because the schedule for the last year was crazy. I literally don't know what film each scene was in, or how they fit together. But we all just buckled down because it's the last one and we wanted to make it as memorable and epic as possible."

Befitting the finale of the biggest film series ever, the special effects, battles and storyline have all been amplified, with a growing focus on Lord Voldemort, his henchmen and the nefarious Death Eaters. It's a shift that bad boy Tom Felton, who plays Draco Malfoy, relished.

"It was great to have an opportunity to really sink our teeth into something and into each other," he asserts, laughing. "It adds a whole different twist to my character which I thoroughly enjoyed."

"It's always very appealing playing a villain," admits Helena Bonham-Carter, reprising her role as Bellatrix Lestrange. "It's so much fun being a tyrant, with no empathy for anyone. I revelled in that, in being a girl with arrested development who orders people around."

"She really enjoys getting into her part," smirks Lewis, recalling a scene he shared with her in Order of the Phoenix.

"She was holding me hostage and I remember she turned to the director and said; 'Wouldn't it be quite fitting - and sinister - if she started to really enjoy torturing him?' Then she started playing with her wand, before sticking the tip in my ear, teasingly. There were lots of explosions going off around us and somehow it suddenly went straight into my ear, about an inch! It actually ruptured my eardrum and hurt like hell - I couldn't hear a thing for a week - but it looked great on camera!"

There are equally sinister and squeamish moments in The Deathly Hallows with Alan Rickman, as Severus Snape, at his sneering best and Jason Isaacs as horrid as ever as Draco's dad, Lucius Malfoy.

"Jason plays an evil sod so beautifully well," sniggers Felton. "He's perfect as a villain. But it's scary how he has the ability to be telling you a showbiz story one minute and as soon as they say 'camera rolling' he snaps into this horrible bastard, who grabs my ear and does all sorts of twisted things.

"I enjoy seeing these amazingly friendly people turn into such horrible characters," he adds, teasingly. "Ralph Fiennes is the worst: it's an eye-opener playing alongside him, because he's such a gentle soul, who's quite calm and measured in his conversation, but then he instantly turns into this twisted, nasty creature the moment we start filming."

Felton admits that, despite originally auditioning to play both Harry Potter and Ron Weasley, he's happy he was eventually cast as Draco Malfoy.

"I don't know what qualities I brought that made them think I could play this satanic child, but I am very grateful they chose me to play the bad guy rather than the goody," he grins. "I revelled in the fact I could vent my day-to-day frustrations through this Hitler-like child; it was actually quite therapeutic and enjoyable."

Although he's enjoyed his role, playing the bullying, demonic Draco, Felton admits there have been a few downsides: namely people misjudging, or mistaking his character for him.

"Yeah, most people struggle to see that I'm not my character. They're usually surprised when they meet me and realise I'm quite a nice guy, not an arse," he laughs. "As for kids, I can't get a handshake, for love nor money, out of them because they're generally terrified and don't want to come anywhere near me! It's as if I'm trying to lure them into the dark side!"

Despite the misperceptions, Felton admits that being involved from start to finish in Harry Potter has been a life-changing experience, with too many highlights to pinpoint one. But now that the journey is nearing its conclusion, he concedes he has bittersweet feelings.

"It'll be sad to leave it behind, because it's been such a big part of my life; it really has been a magical journey, which I've thoroughly enjoyed," he says. "I just hope we do it justice with these last two films, because that's all we really want.

"But, on the other hand, I'm also quite relieved it's over because my whole childhood has been spent doing this. I really can't wait to finally tackle something new.

"Also, I'll finally get to leave the blond hair behind! Dying my hair blond and generally looking like a complete freak became rather tedious," he admits, sighing. "It was the same with holidays: not being able to go in the sun, so that my skin remained pale, became a real pain. Instead of being able to sit on the beach I had to sit under sun umbrellas whenever I went on holiday. So, for me, the best thing about this ending is the opportunity to finally go on holiday and, for the first time, be able to swim in the sea, out in the sun," he jokes, shedding some light on the darkness behind his Harry Potter journey.

What: Harry Potter and the Deathly Hallows
When and where: Opens at cinemas November 19

- TimeOut, additional reporting AP