Despite its dizzying narrative corkscrews, Wong Kar-wai's 2046 can be summed up in two sentences. "I once fell in love with someone. After a while she wasn't there." Beneath the movie's artfully fractured surface beats the heart of a bodice-ripper, not unlike the racy stories unemployed newspaperman Chow (Tony Leung Chiu-wai) churns out to keep himself afloat. The ardent tryster Leung played in Wong's In the Mood for Love has become a debased roué, sporting a pencil-thin moustache and greasy demeanor, half-joking that his heart is for sale, but only retail, not wholesale.

Relocated from In the Mood's Singapore to 1966 Hong Kong, Chow takes up residence in a dingy hotel with membranous walls that his vigorous and frequent lovemaking literally threatens to rupture. Boundaries in 2046 are like that: semi-permeable, sometimes transparent, but always impossible to breach. Past and present, real and imaginary, one person and another: overlapping, almost colliding, but never relinquishing themselves.

Space and time substitute freely for one another. Although the movie's title refers initially to the Chinese government's promise to leave Hong Kong unchanged for 50 years after the 1996 handover, within the world of the film, 2046 (always pronounced as four separate numerals) is a place, not a date. Or rather, places: First, the room where Chow and In the Mood's Su Lizhen (Maggie Cheung) had their regular assignations; second, the room next door to his current lodgings, serially occupied by the hotel owner's two daughters, passionate Bai Ling (Zhang Ziyi) and demure Wang Jingwen (Wong Faye); and third, a futuristic city in one of Chow's stories where people go "to recapture lost memories." The movie's enigmatic, elusive linchpin, 2046 is to Chow what Rosebud was to Charles Foster Kane: a symbol that holds out the false promise of explaining a man's life.

The movie's present, such as it is, spans the years 1966›69, but the anti-British riots outside barely penetrate Chow's self-induced reverie (or, for that matter, Wong's). He's too absorbed in his gadabout life, scribbling stories about large-breasted nightclub singers and ushering an endless (though unseen) parade of women into and out of his bed. Superimposed atop the lovesick Chow of In the Mood, this insincere Lothario is a painful sight, a damaged romantic who has carved out his heart lest it be broken again. When Bai Ling, a dancehall girl who typically charges men for the pleasure of her company, offers to waive her fee for Chow, he insists on paying, a casually cruel gesture that implodes beneath the surface of her carved-ice face. She counters the only way she can, lowering her price to an absurdly low rate and hoarding his ten-dollar bills as if they were love letters.

Their torrid meetings become a love affair in all but name, but Chow recoils when Bai Ling turns serious. He moves on, but the story keeps bringing him back to where he started: another Christmas, another Nat King Cole number, another endless trip to, or maybe from, 2046, where the trains whoosh endlessly through neon canyons but never seem to arrive. In Chow's fantasy land, women are replaced by androids with familiar faces; even Cheung shows up as one, her face bloodless, her body constrained, although so briefly it's barely a hallucination. Driven by a despair too deep to acknowledge, Chow plunges deeper into his story, where the loneliness of his life recurs in coded form; he informs us that the frigid "zone 1224 – 1225," where people must cling to each other for warmth, represents Christmas Eve and Christmas Day. "I made up the whole thing," he says, "but some of my experiences found their way into it."

Shot with grainy sensuousness by Wong mainstay Christopher Doyle, whose five-year stint on the movie apparently ruptured their relationship, 2046 nearly overloads the senses. (Kwan Pun Leung and Lai Yiu-fai are also credited.) By design, it's an easy movie to get lost in. Every surface, from Zhang's sweat-dappled back to the worn patina of a tenement banister, vibrates with an erotic current; even The Hand, Wong's explicitly fetishistic contribution to the anthology film Eros, can't compete with its tactile sensuality. (Aleksei Rodionov's work in Yes comes close.)

But Wong frustrates visual pleasure as often as he luxuriates in it, frequently confining the image to a narrow sliver of screen or blocking the foreground with out-of-focus objects; once, Doyle even appears to pass a piece of warped glass in front of the lens in mid-shot. The movie's elegance isn't as constraining as the jeweled cheongsams that imprisoned In the Mood's Su Lizhen, but more than once a woman throws herself against the edge of the frame, as if she were trying to break out of the movie altogether. Beauty is a trap for Chow as well, in a different sense; consumed by a lost memory he can neither recapture nor escape, he seems doomed to repeat himself with ever-diminishing returns. When he returns to Singapore — a journey that, in tune with the movie's circularity, occurs at its beginning and its end — he finds Su Lizhen again, only this is a different Su Lizhen: a professional gambler (Gong Li) whose permanently gloved hand hides a past hurt she will never divulge.

Wong may be a voyeur, but he keeps his characters' secrets. Although Chow peers avidly through the scrolled ironwork and frosted glass that separate his room from 2046, we never see what he sees, just as we never hear what Su Lizhen (or rather, her analogue inside Chow's story) whispers into the mysterious tortoiseshell orifice that is the movie's most hypnotic and gnomic image. In fact, within 2046 itself, we learn almost nothing about the lost love that has crushed Chow's spirit; Wong has suggested that viewers who haven't seen In the Mood for Love see 2046 first, as if it were preferable not to know too much about Chow's past before exploring his future.

All movies are sculpted in time, but few so literally. 2046 is built, structurally and visually, on circular and linear forms, sometimes both at once: the futuristic tube-trains, whose furnishings replicate their outward appearance; the iron spirals through which Chow peers; and the swirling pattern of the mystery orifice. Even the tears which are the movie's most evanescent motif can be thought of as lines emerging from circles: an attempt to convert a repeating, inescapable past into the forward thrust of the future.

"All memories have traces of tears," an epigraph reminds us, a treacly truism converted into poetic truth by the force of the movie's imagery. We never see Chow cry, of course, and even Bai Ling chokes back her tears until the last instant, her face a squirming mask of constraint. Chow's story does his crying for him, and the movie cries for both of them, a metaphor made literal when Wong fills the screen with a single watery smudge.

Unlike the androids in Chow's story, whose emotions are "slowed by time," Wong's characters feel too much, a vice he obviously considers far preferable to its opposite. The danger is that memories of love lost will trap them in the past, in the sweet promises of a stasis that can never be kept (which, if anywhere, is where the Chinese government comes in). When Bai Ling cries, "Why can't it be like before?" it's as if no one has spoken such words before. You may wonder yourself, Why not?

2046 Written and directed by Wong Kar-wai A Sony Pictures Classics release Opens Friday at Ritz Five recommended