(CNN)—About three weeks' work.
That's what Andy Serkis' agent told the actor in 1999 when he was first offered the role of Gollum in the "Lord of the Rings" films. "They want to see you for the voice for an animated character," he was told.
More than four years later, Serkis' work as Gollum was finally done. And he was far more than a "voice for an animated character."
Gollum, in fact, was a groundbreaking computer-generated character, equal parts Serkis' strangled, haunted voice, his classical acting and the latest computer technology.
The actor's full-bore performance has earned talk of an Oscar nomination and a loyal fan base known to mutter "My precioussss" in Serkis' distinctive gasp (inspired by a hairball-coughing cat).
Although it didn't turn out to be a three-week lark—something Serkis knew from his first meeting with director Peter Jackson and Jackson's partner and "Lord of the Rings" co-writer Fran Walsh—he thought it would be something special. With the encouragement of Walsh, he started keeping a journal.