Back in 1970, when John Cleese invited Terry Gilliam to join the Monty Python troupe, Gilliam was the odd man out. He was a comic book artist, the only American in the troupe, the only one who had no experience of creating verbal and satirical wit, of the kind that had been honed so carefully by all the others in theatre troupes at Oxford and Cambridge. What could he do for them? Well, he made animations - the stomping foot, the statues that did witty things, the weird juxtapositions of images, the transitions from one sketch to another. He didn't act in the TV shows, and in the Holy Grail he played Patsy, the silent groom to King Arthur who clops the coconut shells behind him.

I tell you all this because when Gilliam became a director he filled his movies with visuals that at their best could knock your socks off but otherwise simply detracted from whatever story he was trying to tell. Some movies, of course, don't need stories, but his always have - and so what happens, more often than not, is that his insistence on startling us, or exciting us, or moving us with images, simply undercuts the power or wit of his stories. Whenever he needs to let go of the images and get on with his story, or his characters' development, or a conflict, he seems to cut away to yet another moment entirely. It's as though he assumes we'll get it for ourselves and he can indulge his own flights of fancy.

And so it is with Gilliam's new film "The Brothers Grimm." He's given us two brothers named Grimm, Wilhelm and Jacob, played by Matt Damon and Heath Ledger, but they have less to do with the real brothers, the ones who collected all those fairy tales, than my Aunt Mary. Now that's not automatically a problem, because he has a story that's fascinating to tell no matter who his characters are. It's the story of two con artists at the turn of the 19th century - the brothers Grimm - who trick innocent villagers with magic and leave with the town's money to go on to the next village. But then they come upon a town that's actually in the grip of real magic - children are kidnapped and disappear, the forest is enchanted and dangerous, there's a five-hundred-year-old queen living in a haunted tower, and so on. It's a great setup for the film, but by the time Gilliam is through mixing horror with pratfalls, moving trees and filling the screen with endless visual gags, he's lost his focus and the whole story. He can't seem to make up his mind whether he's doing a comedy, a fairy tale or a horror movie, and when he finally ends the film there's nothing left.