Once upon a time, in the far-off future, there was a little boy constructed of metal and miles and miles of fiber, who dreamed of becoming a real boy, whatever that means. The little boy was tragically misunderstood at every turn and, eventually, was turned away from the bosom of his human family and pushed out into the cold, cruel world. There he suffered and searched until the end of time for his mommy, for someone to make him a real boy, and for the meaning of true love, although not necessarily in that order.

Meanwhile, in another once upon a time, a cranky filmmaker named Stanley Kubrick dreamed of turning the little robot boy's story into a film, but found his plans constantly waylaid by other projects, by financial and logistical complications, and by a little problem that had to do with the basic clunkiness of the story. Eventually, the cranky old filmmaker died and the film was never made.

The End. Or was it?

A.I. (which stands for Artificial Intelligence, not, as some scalawags are claiming, A1, as in the steak sauce) is a Steven Spielberg film of a Stanley Kubrick production. That's what the film's opening credit tells us, anyway, and what it means is that Spielberg directed the movie based on Kubrick's idea and, to some extent, intent. It's an odd hybrid of a movie, combining elements that smack of both filmmakers but not fully in either's camp. It's an intriguing film as well, but, unfortunately, not a particularly great one.

A.I. shows a much darker side of Spiel-berg the filmmaker than we've seen before — even in stuff like Schindler's List and in the bloodier bits of Private Ryan — and that's a realm in which the director doesn't seem completely at home. The film's opening (and most successful) section details the strange and strained family dynamics that occur when the little robot boy, David (Haley Joel Osment), is brought home to a human mother and father mourning for their dead-yet-living, cryogenically frozen child. As physically adorable and desperate for love as the little "mecha" David is, there's something creepy about him too. It's not just that he's so like us and yet so unlike; David is eerily formless, a tabula rasa: A blank slate waiting to be imprinted with emotions, an empty vessel waiting to be filled with whatever happens to come along.

Spielberg and master cinematographer Janusz Kaminski shoot all of this in an elegantly stilted, oddly composed style that emphasizes the tension and just plain weirdness of adjusting to life with David. Mom (Frances O'Connor) eventually makes the leap to accepting and then loving the little robot boy, but that's when things really get strange: The couple's terminally ill human child suddenly, mysteriously recovers and then returns home as damaged goods with an agenda of making life hell for his mechanical "brother." From there, it's a short trip to David being cast out of Eden and left to fend for himself in a big, bad world that isn't particularly friendly toward non-humans. The rest of A.I.'s considerable running time amounts to a series of flashy but formless and very tenuously connected sequences in which the little mecha drifts from one exotic, futuristic environment to the next, in a vaguely defined quest to find Pinocchio's mythical blue fairy, who he's certain will turn him into a real boy.

Individual moments in the movie are quite good, but A.I. doesn't really hold together, and it never comes to grips with what it really is — a tragedy of epic proportions. Spielberg just can't seem to let go of the desire to present us with a fairy tale to make us smile through our tears, and the movie ultimately becomes awkward and repetitious as it drags on, straining to find just the right series of upbeat notes in what is essentially a rather dour, discordant piece. The Pinocchio parallel is an already obvious one (the toy who would be a boy), but Spielberg makes it into some half-baked boomer mantra and then beats us over the head with it for nearly two-and-a-half hours.

Kubrick, who might have shaped this material in a more satisfying way, is paid tribute to throughout, from sly little visual nods to the white decors and bubble cars of A Clockwork Orange, to Alex's nasty soft shoe in that same film. By the end of A.I., though, Spielberg's rambling movie is trying to set itself up as 2001, with an extended finale that, in scale and scope, seems to be trying to one up the metaphysical journey that begins and ends in the star chamber at the end of the universe. It's a game attempt, but an ultimately empty one; Spielberg's strengths lie in the depiction of strong, pure and, at root, simple emotions, and he's out of his depth here. E.T. is E.T. and, with its complex and potentially unsettling underbelly, A.I. should have just been A.I., and never the twain should meet.