TRAPPED IN NEW YORK'S Soho district, Paul Hackett is Desperately Seeking Sanity, encountering manic-depressive prom queens, time-warped cocktail waitresses, avenging ice-cream truck drivers and shaver-brandishing slam dancers around every corner. For Paul, the evening had begun innocently enough, running into Beautiful Stranger Marcie (Rosanna Arquette) at a mid-town diner as each pretended to enjoy a solitary meal. In no time at all, the two exchange phone numbers, and after checking the cable T.V. schedule for the evening, Paul decides to try his luck with the lady from uptown. Tempting him with the prospect of purchasing one of her off-beat roommate's bagel and cream cheese sculptures, Marcie invites our hero to... what else?... her loft for a post--midnight nightcap. And so another unsuspecting Daniel enters the lion's den.

Heir presumptive to Jean--Jacques Beneix's Diva and Susan Seidelman's Desperately Seeking Susan, After Hours meanders along to the beat of a surrealistic cinematographic drummer by photography director Michael Ballhaus, who captures that side of New York that Mayor Koch hopes we don't see. Not that Soho after hours doesn't look like an interesting spot, offering the prospective tourist an endless range of entertainment possibilities, ranging from punk rock clubs decorated in a nouveau underground garage to slimy bars frequented by leather and spike clad homosexual bikers. But this is not the kind of thing New York Air tells the folks from Des Moines about. As the camera pans across the city streets slicked down a la Miami Vice, we find ourselves inexplicably drawn to the omnipresent danger and bizarreness that fills the air like sour sushi. But, as Paul discovers for himself, the quiet life in a yuppified downtown appartment has a certain appeal all its own.

APART FROM the film's funky look, After Hours boasts two virtuoso perfomances bolstered by Scorcese's typically brilliant direction. As the Black Widow Spider who spins a web of mysterious boyfriends, ex-husbands and bizarre ailments around herself to the befuddlement of the White Boy from Long Island, Rosanna Arquette firmly establishes herself as the reigning queen of the cult classic. Back on the now--familiar streets of Soho after a temporary migration west in Silverado, Arquette puts her character through its requisite paces of schizophrenia with all the felicity of a chameleon. Newcomer Griffin Dunne is the perfect lukewater Romeo to his elusive Juliet, stumbling through the night as King fool losing his keys, cash and prospective girlfriend in the bargain. Peering around with his puppy--dog eyes, Dunne is archetype Lost Boy--eager to find his way home, but predictably curious about the native customs. Together, they've got to be the most outlandish cinematic couple since Harold and Maude.

As for Director Scorcese: what can one say about a man who can go from Raging Bull to King of Hearts to After Hours without missing a beat? Aiming at a younger audience this time with stars Arquette and Dunne, Scorcese is sure to garner a loyal following among the under-20s rushing to get a glimpse of New York After Hours.