One day Horton the elephant (Jim Carrey) hears a voice coming from a tiny floating speck. Somewhere down there in the microcosm is a miniature planet occupied by the Whos, an eternally optimistic race now facing disaster. Horton, being a kind-hearted soul, lodges the speck in a flower and resolves to carry them to safety. Along the way he's mocked and opposed by the other animals who believe that if you can't see something, it doesn't exist.
And that's about it really: Doctor Seuss' charming children's tale can be read in a lazy quarter hour. The problem faced by Horton the movie is how to stretch such a thin fable into 90 minutes. Still, at least they've got the look right. After the dismal, freakish failures of The Grinch and The Cat In The Hat, Hollywood seems to have finally learned its lesson: don't turn Dr Seuss books into live action movies. Horton takes the far more sensible route of computer animation, and perfectly captures the scrawny, scruffy, floppy elegance of Seuss' drawings.
Horton is like two very different cartoons run together in the washing machine. One features typical Seussian rhyming couplets, a sweetly absurd sense of humour, a wonderfully scary villain (Will Arnett, channelling Bela Lugosi as Vlad the vulture) and a brain-boggling concept. The other has Jim Carrey doing Arnold Schwarzenegger impersonations and features endless pop culture riffs on everything from Japanese anime to MySpace. This sort of thing is standard procedure for most CG cartoons nowadays (and they're going to look pretty silly in ten years, when no-one gets the references any more) but in the case of Horton it's easily forgiveable, because the anarchic slapstick is occasionally inspired and the quieter, Seussical material is very charming indeed.
Horton Hears A Who! is out in the UK on 21st March 2008.