Alan Rudolph is an actor's director. That is, he creates for his performers space enough to inhabit their characters. Which is to say, his films - at least those on which he's more than hired hand - often have an emotional currency at odds with the slick surface of your average 'relationship' picture. His years with Robert Altman (here producing) have been well spent. Which is just as well with Afterglow, whose story is paper-thin but whose undercurrents run deep.

It's about four people. Lucky (Nick Nolte) and Phyllis (Julie Christie), are an ageing married couple who survive on the unspoken rule that she must never see any of the female clients he flirts with.(He's Lucky "Fix-It" Mann, odd-jobber and, as it says rather hopefully on the side of his truck, entrepreneur.) And there are the Byrons, Marianne (Lara Flynn Boyle) and Jeffrey (Johnny Lee Miller), an ostensibly successful young couple with a swanky apartment and, lucky for Lucky, a busted door lock. She is repressed, he is surly and neglectful, refusing sex, especially when she wants a child.

Or maybe Afterglow is really about two people, one of whom never appears and the other who never speaks. These are the children - Marianne's unborn, and Phyllis' daughter, Cassie, who ran away after her mother, a former horror movie star, admitted the father was not Lucky but a lucky fellow actor. That's why they moved up to be near the city (Montreal standing in for Rudolph's familiar Anywhere North America), in hopes they might find her.

Afterglow is hermetic, every bit as self-contained as the world in which it operates. It might have something to do with money, but it is just as likely that Rudolph has little interest outside the matter to hand. The result, however, is that unlike most other movies we do get to know these people inside out. Even the obnoxious stuff-shirt Jeffrey, played with sadistic emptiness by the British Miller. Boyle, an actress who only ever seems to come alive under Rudolph's instruction (evidence her heart-breaking turn opposite Matthew Modine in his masterpiece, Equinox), is superb as a woman suddenly discovering life.

The star power, though, inevitably comes from Nolte and Christie, the latter earning a well-deserved Oscar nod for a dazzling turn as tragic heroine. She is able to play a scene in which two men hang on her every word and convince us that, were we there, we would be no less rapt. "You are the most fascinating woman I've met in my entire life," says Jeffrey. "Yes, I know," she replies. Nolte plays it like he doesn't care, and that's precisely the tone the role demands, so that when he's given the film's emotional tour de force to carry, it hits with the authority of an express train. His are surely the most expressive eyes in contemporary movies.

This is tremendous stuff, from one of the most singular and engaging of all American film-makers. Few if any would have chanced the bawdy, borderline-farcical ending here with its knock-down get-up slapstick fight between Miller and Nolte. Nor attempt to top it with a gut-punch finale that would melt even the hardest of hearts. Afterglow is the sort of film that's too good to make money, but good enough to make lifelong friends.