Peter Jackson has a message for J.R.R. Tolkien: I can’t quit you.

Nearly a decade after the New Zealand filmmaker concluded his massively successful "Lord of the Rings" trilogy — a string of films that grossed more than $2.9 billion worldwide, capped with a best picture Oscar for 2003’s "The Return of the King" — Jackson is set to launch yet another three-film series from the fantasy novelist’s other famous tome, "The Hobbit."

Unlike his previous trifecta, Jackson wasn’t the original filmmaker behind the "Hobbit" films (Guillermo del Toro was initially set to direct, with Jackson producing), and there were supposed to be two, not three, "Hobbit" productions. Warner Bros. executives were so excited after seeing a rough cut of Dec. 14’s "The Hobbit: An Unexpected Journey" that they ordered one more movie, forcing Jackson to reassemble his cast and crew the very summer day he was supposed to be marking the conclusion of production.

"It was announced to us the day of the wrap party," said Martin Freeman, who plays Bilbo Baggins, the reluctant hero at the center of "The Hobbit." "But we had an embarrassment of riches."

The second film, called "The Hobbit: The Desolation of Smaug," is due in December 2013, with the concluding entry, "The Hobbit: There and Back Again," scheduled for July 2014.

Readers of Tolkien’s 1937 children’s literature classic might be startled to hear that two, let alone the idea of three, movies could be spun out from what is not only a rather slim novel but also a book that’s heavy on episodic action and very light on back story.

The book’s central conceit is a quest led by the wizard Gandalf (reprised by "Lord of the Rings" veteran Ian McKellen) to recover treasure guarded by a dragon. Gandalf and Baggins are joined on their journey by a band of dwarfs, who jointly or separately must battle goblins, a vaguely humanoid Gollum (Andy Serkis, another "Lord of the Rings" alumnus), giant spiders, wolves, elves and the dragon known as Smaug.

Jackson said the three films, whose screenplay was written by Jackson, his partner Fran Walsh and Philippa Boyens, draw heavily on Tolkien’s appendices to "The Lord of the Rings," which was published nearly two decades after "The Hobbit." While those additional materials are known mostly to a small circle of fantasy fiction fanatics, Jackson said they provided him and his filmmaking team more than enough flesh to hang on the "Hobbit’s" bones.

"There’s a lot of material, a lot of action, a lot of adventure," Jackson said. "And so what we did is we decided at the very beginning that we would take as much of that material as we needed to and we would expand it."

In two specific examples, the appendices were used to explicate Gandalf’s history, and how he came to work with the dwarf Thorin (Richard Armitage). The supplemental material also helped Jackson create more of a story for Gollum, who makes only a brief appearance in "The Hobbit."

Yet even if Jackson and his team had what they believe was more than enough story, the director was forced to scramble when Del Toro abandoned the project. The "Pan’s Labyrinth" director, frustrated that the financial collapse of co-financier MGM kept the "Hobbit" movies from officially starting, left the two films in May 2010 after spending nearly two years preparing his productions.

Jackson briefly considered implementing some of Del Toro’s designs, and concluded he couldn’t shoot another filmmaker’s movie.

"He’s an incredible visionary guy and all his designs were Guillermo’s designs," Jackson said. "I thought, if I’m going to do it I need to actually be comfortable, to do the thing that I want to do in my head. So I suddenly found myself scrambling. I was literally scrambling to get designs ready on time for the film that I wanted to make. And we were revising the script furiously. The delay didn’t help anybody. It didn’t help him. It didn’t help us. It didn’t help the film."

In not only "The Lord of the Rings" but also in "King Kong" and "The Frighteners," Jackson has excelled at creating memorable creatures, and "The Hobbit" provides a great test: Smaug is arguably one of the best-known dragons in literature, and yet moviegoers of all generations believe they know what a dragon, not just Tolkien’s fearful beast, should look like.

"The trouble with redesigning dragons is that if you really get fruity with it, it suddenly starts to look like some sort of monster from another planet — you very quickly can go into science-fiction territory," Jackson said. "I don’t want to do that. I mean, people expect a dragon. ‘The Hobbit’ is one of the most famous dragon stories in the world, really. So I’m not trying to step away from the dragon. I just want to present the most venal, scary, decrepit, nasty dragon that I possibly can."

Perhaps Jackson’s greatest storytelling challenge is Tolkien’s almost steadfast refusal to engage in exposition and allegory. People can read into "The Hobbit" whatever they want, but Jackson isn’t going to help confirm anyone’s theories.

"I just like to tell stories," Jackson said. "I don’t set out to try to preach to people and put hidden meaning into things. I just think if you can entertain people and give people a good time at the movies you’re doing your job well. I don’t think it’s any more complicated than that."