What if you aren't who you think you are? What if your memories are manufactured? What if otherworldly beings slip into your mind while you sleep, changing your identity as casually as one changes TV stations? That's the premise of Alex Proyas' striking new sci-fi noir thriller. He calls it "Dark City." Mental health professionals might call it "Paranoia Helper."

Using extremely quick edits, sensuous computer graphics, and a palette of blacks, browns and blues, with an occasional splash of red, Proyas ("The Crow") puts you smack in the middle of a nightmare from which you cannot awake. The story employs a fractured dream logic, although attentive viewers will have no problem following the narrative flow.

You could spend hours listing all the film's reference points. "Brazil," "Blade Runner," "Altered States," "Metropolis," "Twin Peaks," and "The Prisoner" spring to mind, but there are many other touch points. The bottom line, though, is that Proyas has crafted a vision distinctly his own. "Dark City" has an amazingly rich texture and an extraordinary sense of place. Even as the buildings themselves twist from one shape to another, you feel as if you could walk down their desolate halls. Despite periodic lapses into cheesiness, "Dark City" is memorable filmmaking, more an experience than simply a movie.

It begins when John Murdoch (Rufus Sewell) wakes up in the bathtub of a seedy hotel suite. There's a dead prostitute in the room, but he can't remember if he killed her. For that matter, he can't remember anything about his past. While desperately trying to collect himself, Murdoch receives a call from a Dr. Schreber (Kiefer Sutherland,) urging him to flee the room immediately. In short order, Murdoch learns that a lot of people are looking for him. Inspector Frank Bumstead (William Hurt) wants him in connection with a string of vicious murders. His wife Emma (Jennifer Connelly) wants to make amends for cheating on him. And the Strangers want him very badly. Bedecked in long overcoats as they silently fly through the night skies, the pallid bald pursuers look like the hellish spawn of Uncle Fester and Pinhead, filtered through a Magritte painting.

So who are the Strangers and what are they up to? It would be best to find out during the course of the story, but since Proyas spills the beans in an unnecessary voice-over at the beginning of the film, I'll recount them here. The Strangers are the last of an alien race, conducting experiments on humanity from their headquarters deep beneath the city. Possessed of a power called "tuning," they can stop time, make people fall asleep with the wave of a hand, and reshape physical reality through concentration alone. At the stroke of twelve every night (and it's always night,) they implant memories and identities in various citizens, then carefully watch the results.

But sometimes the implants don't go quite right, as evidenced by Murdoch. Further complicating the Strangers' agenda is the fact that Murdoch is also able to tune. Gradually, Murdoch changes from panicked victim to avenging warrior as he pursues vague memories of an idyllic place called Shell Beach, all while honing his newfound powers. Clearly it's just a matter of time before he confronts the aliens and dares them to "Go ahead, make my night."

Rufus Sewell handles Murdoch well, investing the character with just the right amounts of urgency and strength. Hurt and Connelly turn in sturdy enough performances, given the befuddled nature required of their characters. Richard O'Brien, who created "The Rocky Horror Picture Show" and played Riff-Raff, gives a stylish turn as Mr. Hand, lead hatchet man for the Strangers.

The oddest performance comes from Kiefer Sutherland, affecting a bizarre, quasi-Peter Lorre impression as Dr. Schreber. Sutherland says two...or three...words then he...pauses and...breathes then he...continues speaking. The halting, breathy speech style is just as annoying onscreen as it was in that sentence.

Performances and plot aside, "Dark City" is a feast for the eyes. The city has the worn look of New York in the 40s or 50s, with retro funkiness and art deco flourishes everywhere. Computer animated shots of the buildings morphing from one shape to another are dazzling, as are the scenes of the Strangers gliding through the air. The effects are occassionally cheesy, particularly when Murdoch has a literal battle of wills with head Stranger Mr. Book (Ian Richardson,) but with a vision as expansive as Proyas', the flubs are easy to overlook.

With it's roots firmly in the "Heavy Metal" school of adolescent trippiness, "Dark City" makes no groundbreaking statements, but that's fine. Proyas has taken a clever idea, added some phenomenal imagery and created one whale of an apocalyptic dreamscape. During a season where most movies look like photocopies of each other, "Dark City" is a most welcome diversion.