Secrets of the ring

Tolkien fanatics feared the worst when Peter Jackson revealed his plan for a digital Gollum for The Two Towers, the latest instalment of his Lord of the Rings trilogy.

Instead, he has delivered a cinematic breakthrough and created a disturbing and touching character. "We wanted Gollum to be non-human, but we also made a key decision that we wanted to cast an actor in the part," Jackson says. "When we first met Andy Serkis, we said: 'You're going to have to work for three years, but no one is ever going to see you in the films.'"

Serkis had to wear a skin-tight blue Lycra suit for the part, moving about the set and imbuing Gollum with the timing, nuances and reactions that only a live actor can bring.

"Then we painted Andy out of the scene before putting our computergenerated Gollum over the top of him," Jackson explains. "When Andy later did the voice, we filmed his face and every little twitch and muscle reflex, which the animators exactly copied. They did an incredible job. In fact, the two look like weird cousins."

So ground-breaking is Gollum that Serkis could wind up with an Oscar nomination as Best Supporting Actor. Those pushing for such an accolade cite John Hurt, nominated for his performance as the deformed John Merrick in The Elephant Man as a precedent. "Obviously, I wouldn't turn it down if it was offered," Serkis says. "The way I see it is, it's an acted role in which I have genuinely created the voice and physicality."

Making a convincing Gollum was just one of the challenges facing Jackson in bringing Tolkien's epic vision to the screen. One of the highlights of The Two Towers is the battle at Helm's Deep. It's a relentless 30-minute-plus sequence in which warrior Aragorn (Viggo Mortensen) leads what could be humankind's last stand against the forces of evil, the 10,000 strong Uruk-hai army.

To help create the battle scene on such a breathtaking scale, Jackson's in-house special effects company, Weta Workshop, created a miniature Helm's Deep before buying 75,000 plastic miniature medieval soldiers, which the director used to help choreograph the fight sequences.

And for whatever couldn't be accomplished with the miniatures, Jackson and his huge crew took to a quarry not far from Wellington, New Zealand, drafting in tens of thousands of extras and horses (propmakers created 48,000 pieces of armour for the trilogy and more than 10,000 arrows), shooting outdoors and at night.

Jackson and his team later asked a 25,000 strong crowd of cricket fans at Wellington Stadium to chant, stomp their feet and beat their chests in order to create sufficient noise for the epic scene's soundtrack.

"It took about three and a half months of night shoots to film Helm's Deep - enough to make a whole movie," Mortensen says, "but you only get a very small part of what we did. It was one of the more difficult periods of making the trilogy, but it was one of the most memorable."