The movie version of "The Chronicles of Narnia: The Lion, the Witch and the Wardrobe" won't be out until Dec. 9, but dozens of books already are spilling out of the cupboard.

"Sales since the 'Wardrobe' movie trailer was released in May are three to four times more than last year at this time," said Beth Bingham of Borders bookstores.

Borders and other stores nationwide are prominently displaying the books. Amazon.com and Barnesandnoble.com have set up special Narnia stores on their sites.

"Wardrobe," written by C.S. Lewis and first published in 1950, is part of the seven-book "Chronicles of Narnia" series and tells the story of four children who help the lion Aslan release the frozen, other-worldly land of Narnia from the White Witch's spell. Aslan is regarded by many readers as the allegorical Christ — though Lewis always said it was not a Christian allegory.

Bookstores, for the most part, are sidestepping the question.

Joe Monti, a book buyer for Barnes & Noble, agrees that "Chronicles" "has this whole Christian level to it." But, he adds, "the fantasy elements resonate on so many different levels. Who doesn't want to step into another world?"

HarperCollins, which is the exclusive English-language publisher of Lewis' works worldwide, says it is not targeting Christian buyers. "Our position has been and always has been to publish "Chronicles" to the broadest possible market and leave any interpretation to the reader," says Toni Markiet of HarperCollins.

And the market appears broad. HarperCollins Children's Books has 25 movie tie-in products, including books, audiobooks and coloring and activity books. HarperCollins publishes 170 titles by or about Lewis; 140 are on or about Narnia. Other publishers are hoping to take advantage of Lewis' growing popularity by releasing biographies, guides and analytical works. One of the new entries: "Jack's Life: The Life Story of C.S. Lewis," written by his stepson, Douglas Gresham.

In his lifetime, the scholarly Lewis published about 50 books, including such theological mainstays as "Mere Christianity" and "The Screwtape Letters." Books analyzing his works number in the hundreds. But it was "The Chronicles of Narnia" that made him famous — just as "The Lord of the Rings" brought renown to his friend and contemporary J.R.R. Tolkien.