The film is adapted from William Steig's 1990 picture book, and the credit is on screen. What it takes is small and load-bearing: an ogre who is happy being an ogre, sent out into the world, who rescues a princess as ugly and as pleased about it as he is, and a story that refuses to make either of them beautiful at the end. Filed LOW deliberately. Steig's book is about thirty pages and has no Donkey, no Farquaad, no Duloc, no fairy-tale refugees and no swamp to defend. Almost everything an audience remembers about Shrek was invented for the film. What the book supplied was the premise and the tone, and the film could not have started without them.