Based on the Caldecott Medal-winning children's book by Chris Van Allsburg, The Polar Express makes a marvelous transition to the silver screen. Children's books don't always fare so well. Look no further than last year's Cat in the Hat for an example of a children's book that fell flat when translated by Hollywood. Slim children's books like The Polar Express and Cat in the Hat require a considerable amount of expansion in order to fill out a feature length running time. Cat in the Hat collapsed because of its misguided expansions, which provided nothing more than irrelevancies that distracted from the simplicity of the storytelling. The Polar Express also gets opened up, but there is much more between the pages of The Polar Express than in Cat in the Hat.