Being John Malkovich.

Thanks in no small way to Cameron Diaz and Catherine Keener, the wildly inventive Being John Malkovich is a sexy, gender-bending trip

Being John Malkovich * Written by Charlie Kaufman * Directed by Spike Jonze * Starring John Cusack, Cameron Diaz, Catherine Keener, John Malkovich * Gramercy

If we could burrow inside the head of writer Charlie Kaufman, we would probably find a roguish 12-year-old with simmering heterosexual longings. Who else but a child could conjure a story as impulsive, unbuttoned, and oblivious to rules as Being John Malkovich? Who else but a pubescent child could still see sexuality as a land with permeable boundaries? Who else but a heterosexual pubescent boy--and an eccentric one at that--would fantasize about getting inside the head of actor John Malkovich?

If I thought you'd go see this film on just my word, I'd stop right here. The less you know about it, the better the ride. Being John Malkovich is a nervy fun house of a movie whose laughing goblins, eerie cul-de-sacs, and surprise detours depend on an unspoiled perspective for their greatest impact.

But it won't hurt you to learn that John Cusack stars as Craig Schwartz, a down-on-his-luck New York City puppeteer whose esoteric art keeps audiences away in droves. Affecting a sloped-shouldered, downtrodden posture that radiates pain and unrequited longing, Cusack is the embodiment of the defeated Everyman. Stuck in a doting but flat marriage to a sweet petshop worker named Lotte (Cameron Diaz, winsomely deglamorized beneath a frizzy Alice in Wonderland spray of brown hair), he sublimates all of his passions through his wooden doll surrogates.

Hitting rock-bottom, Craig takes a file-clerk job for a firm that is even stranger than his puppet shows. It's located between the seventh and eighth floors ("low overhead" is the company joke), the executive secretary (the divine Mary Kay Place) is a hearing-impaired specialist in speech impediments, and the boss (yikes, it's Orson Bean) is a 105-year-old fool for love and carrot juice. Craig falls hard for the only semi-together employee at the place, a homophobic ice queen named Maxine (Catherine Keener) who won't give him a tumble. Keener is all crocodile smiles and Veronica Lake-frost in the role, wittily outbitching her malcontent Mrs. Ben Stiller in Your Friends & Neighbors.

But there's this little door, you see. Craig finds it behind a file cabinet, and when he opens it up he is whooshed down a long dark tunnel and into the head of John Malkovich. There he dwells for 15 minutes and then is summarily dumped onto the shoulder of the New Jersey Turnpike.

Craig and Maxine smell a gold mine. Think of the possibilities: You can loiter inside the ever-cool, everbalding Malkovich while he brushes his teeth, orders towels from a catalog, and, yes, has sex! When boring little Lotte takes the Malkovich trip, it opens up new sexual horizons within her. Soon after dusting herself off from the side of the Jersey Turnpike, she finds she is vying with her husband for Maxine's love.

Produced in part by rocker Michael Stipe and Sandy Stern and directed by Spike Jonze with a dry, Brazil-ian flair for potty behavior and off-kilter environs, Being John Malkovich scores on many levels. As theatrical metaphor, it toys with the mutual yearning that binds actor and audience: The actor thrives by inhabiting all manner of people, while the little people they emulate bum to know, if not be, them. As a comic fugue of sexual liberation, it diabolically points up the absurd lengths to which most of us would have to go to transcend our rigidly imposed sexual identifies.

Malkovich is the perfect conduit for such a journey. Sly and subversive in his low-burning performance style, he projects an ambiguity of both intent and sexuality. Malkovich wears his masculine and feminine sides openly and confidently, and he throws himself into the movie's daffy looking-glass world with a fever-dream intensity and self-mocking glee. If he could see his way toward a few sit-ups and a low-fat diet, his masculine and feminine admirers might want to inhabit his body as well as his mind.

Stuart is film critic and senior film writer for Newsday.