On Friday, Walden Media and Disney released "The Chronicles of Narnia: Prince Caspian," the sequel to the wildly successful 2005 film "The Lion, The Witch and the Wardrobe." The filmmakers faced the challenge of turning a beloved book with a slow plot into a modern film that retains the story's spiritual messages.

''The underlying messages are so important, and so vital to the story,'' says Douglas Gresham, Lewis' stepson and co-producer of the new film.

''Which are the return to faith, truth, justice, honesty, honor, glory, personal commitment, personal responsibility. Also the message [that] no matter how far away we stray, there's only one way back.''

The first Narnia book, The Lion, The Witch and the Wardrobe, told the story of four Pevensie siblings who enter Narnia through an old wardrobe and defeat the tyrannical White Witch. They are aided by the great lion Aslan, but only after he submits himself to be killed in the place of turncoat Edmund Pevensie. The book is widely regarded as a retelling of Lewis' Christian faith, with Aslan shining as a golden Christ figure who returns after death.

In Prince Caspian, the children return to Narnia (this time through a tube station near London's Trafalgar Square). Although they are only a year older, 1,300 years have passed in their former kingdom. The evil interloper Miraz has stolen the throne from Prince Caspian and forced the true Narnians into hiding.

Aslan has not been seen in centuries. Each character in the movie faces the same crisis: They long to see Aslan but he remains elusive. William Moseley, who plays Peter Pevensie, sees the search for Aslan as a metaphor for faith.

''When you talk about seeing, I think it's more believing,'' he said. ''You believe, and then you see. Aslan represents God. People say, 'If God's there, why can't I see him?' Well, because you're not believing.''

The movie format necessitated some changes to the book's storyline.

''Essentially, the book is a long walk followed by a short battle,'' says Andrew Adamson, the film's director and producer. He rearranged the time line to put more action at the beginning and expanded the battle scene.

He also had to leave out some beloved scenes and characters.

Such sacrifices allow more room to fully explore such characters as Reepicheep the valiant mouse and Trufflehunter the faithful badger.

* Read Sean P. Means' review of the film at www.sltrib.com.