The story of Frankenstein, says Aaron Eckhart, is all too familiar. It is the tale of a man-made monster who is an outcast from society. Yet for Eckhart, the creature is ''the monster inside all of us''.

''All the insecurities, all the doubt, all the self-loathing - that's what attracted me to the part. We all feel that we are unloved and unworthy. We have all these deficiencies that we have to overcome. And that is how I see this character.''

Eckhart (The Dark Knight, The Company of Men ) plays Frankenstein's creation in a new movie by Australian writer-director Stuart Beattie, whose screenplays include Collateral and Pirates of the Caribbean, and who wrote and directed Tomorrow, when the War Began.

I, Frankenstein was shot in Melbourne, apart from an Arctic sequence filmed in winter in Argentina. It begins in the late 18th century, then switches to the present. It is set in an unnamed urban location, a kind of modern-Gothic metropolis, haunted by supernatural figures from a struggle that has gone on for centuries. The monster in this case is an action hero, forced to take sides in a cosmic battle between two supernatural forces.

On set during filming, I watch a fight sequence shot late at night in an old building in the centre of Melbourne. It's a fierce one-on-one combat, with Eckhart wielding a pair of fighting sticks, throwing himself furiously into the scene.

Later, he sits down beside his trailer to talk, lights up a cigar and begins to riff on monstrosity, adolescence and the need for a purpose in life.

He switches between ''he'' and ''I'' when he is talking about the creature and the burden he carries - part physical, part psychological.

''My character is without purpose. He doesn't know his purpose, and any man or woman who doesn't know why they are here or who doesn't have an interest that propels them through life is damned in a way,'' he says.

This is what the monster seeks - a reason to be who he is or become something else.

''There's nothing worse than roaming the world without purpose, especially when no one is going to take you in. I can't go to the hotel. I can't go to a 7-Eleven. They'll probably kick me out of this park, because I scare children.''

His character has the capacity to do harm, he says. He looks monstrous. The audience might think of him as a violent figure, a killer. ''But he's drawn to the light.''

There is one consistent theme in Eckhart's approach to his work. As an actor, he says, ''it's your job to humanise everything. I never play bad guys. I play people who maybe do bad things and believe that they are good. That really is the only way to play it, the only interesting way.''

The creature might be battered and burdened, but Eckhart regards him as something of a child. He returns constantly to the father-son dynamic of the Frankenstein story and to the tale as a metaphor for adolescence and its discontents.

In some ways, he says, this is a film for teenagers. They will see ''an archetypal action movie about a boy becoming his own man, separating from his father''.

Frankenstein's monster was born in 1816, emerging from the imagination of a young woman in her teens. The character came to Mary Shelley in a dream. Two years later, she published Frankenstein: Or, the Modern Prometheus, the story of a scientific experiment whose ramifications still resonate.

It is a story that keeps on morphing. Frankenstein has been constantly explored, remade, referenced, in forms that range from horror to comedy, from tragedy to trick-or-treat homage, and James Whale's 1931 movie version became an influence in its own right.

Mel Brooks' Young Frankenstein is an affectionate tribute, while Spanish filmmaker Victor Erice's haunting The Spirit of the Beehive is an extraordinary response to the psychological resonances of Whale's film.

In Abbott and Costello Meet Frankenstein, the strange and the slapstick jostle for screen time, while in Tim Burton's Frankenweenie, a boy seeks to bring his dog back to life.

Beattie's take is a mix of elements and influences. He was approached to make a Frankenstein film based on a graphic novel concept by Kevin Grevioux, the actor and writer who co-wrote the first Underworld film and helped set the vampires-versus-werewolves franchise in train.

Grevioux's notion was the monster reborn as a private eye, but Beattie suggested something else. To the story of the scientist and his hapless creation, he added another element: a struggle between good and evil, ''an ongoing war between two supernatural races, the gargoyles and the demons''.

In I, Frankenstein, Bill Nighy plays the suave head of an international biotech corporation. Yvonne Strahovski (Chuck) is a research scientist working on the effects of electrical stimulation on the dead. Miranda Otto is the stately queen of the gargoyles. Jai Courtney is her trusted offsider, suspicious of the monster and his intentions. Aden Young plays Dr Frankenstein and Grevioux has a role as a demon henchman.

In creating a world of supernatural face-offs, Beattie says, ''I came up with a way to make Frankenstein's monster organic to that.'' The character has the capacity to be used by either side in the struggle. He has a secret that the demons need, but is it clear what the monster will do?

''Humanity has always been cruel to the monster, from the beginning, so why would he care about saving them?'' he asks.

Beattie emphasises that he set out to make a work of entertainment. I, Frankenstein was always meant to be a popcorn movie, made with attention to character and story. His first cut was two hours and 20 minutes, but the film now runs for little more than an hour and a half.

''There was a lot of insistence by the studio to make things go faster,'' he says.

He is very happy with the visual effects, which were done on a surprisingly limited budget. The idea of converting to 3D had been discussed at various stages, but it was only in post-production that the decision was made.

What's gone in the abbreviated version is much that establishes character, he says. Several scenes between the monster and his maker were lost.

''Great scenes when they were going at each other and Victor [Frankenstein] promised to make him a companion, and then reneged on that promise. The whole hunting of the monster through the centuries by one of the demons, a Javert-like character - all sorts of stuff like that, they just kept cutting.

''I'm still proud of the film and the work that was done on it. I think it's fun and entertaining. But there's a lot of stuff that got taken out that I wish hadn't been.''

I, Frankenstein opens on Thursday.