What director Darren Aronofsky did for Mickey Rourke and wrestling in 2008's "The Wrestler," he does for Natalie Portman and ballet—with a macabre bent—in "Black Swan," an enrapturingly inventive psychological drama that dabbles in several different genres and defies easy categorization. On the one hand, it's a vividly conceived character study about a young woman's overwhelming drive to succeed at the prestigious, but ultimately fleeting, profession she has chosen. The often handheld camerawork by cinematographer Matthew Libatique (2010's "Iron Man 2") never stops following the protagonist, frequently from behind like an invisible guardian angel, almost disappearing within her shoes. What she goes through, the viewer goes through, her accomplishments and downfalls meaning all the more because of Aronofsky's blistering human snapshot. Not stopping there, the picture also works as a mystery, as a candid glimpse into the disciplined, physically grueling, sacrificial world of ballet dancing, and as a colorfully artsy horror film of the sort Dario Argento might have made decades ago (echoes of 1977's "Suspiria" cannot be a total coincidence).

As a member of a distinguished New York City Ballet company, Nina Sayers (Natalie Portman) is well into her twenties and sensing that if she ever hopes to rise to the top of the ranks among her colleagues, she'd better do it soon. A splendid dancer whose sharp technique gets in the way of her outward passion, creative director Thomas Leroy (Vincent Cassel) is unsure she has what it takes to play the dual lead roles of the White Swan and Black Swan in an upcoming production of "Swan Lake." Through a little luck and a fateful private encounter with Thomas, Nina nabs the part, leaving longtime, over-the-hill prima ballerina Beth MacIntyre (Winona Ryder) out in the cold. Nina is thrilled to finally have the star turn, and so is her domineering mother Erica (Barbara Hershey), but the rigors of rehearsal slowly begin to get the best of her. Overworked and increasingly paranoid that new fellow dancer Lily (Mila Kunis) is conniving to steal the role from under her, Nina's mental state unhinges with grisly results as opening night draws near.

Physically and dramatically, Natalie Portman (2009's "Brothers") is nothing short of stunning as Nina Sayers. Having trained for six months prior to shooting, a lithe but fittingly muscular Portman looks every bit like the ballerina she's playing, and the lack of cutaways for stunt performers and stand-ins ensure that she does nearly all the dancing herself. It's an amazing transformation, one that Portman has clearly given her full body and soul toward. When Nina discovers she has won the coveted lead in "Swan Lake" and drops into a bathroom stall to call her mother and give her the good news, her utter elation is so infectious it's impossible not to smile. Alas, that happiness is short-lived as Nina gets down to business and starts struggling to capture the sexual ferocity of the Black Swan. All the while, director Darren Aronofsky paints a visually foreboding, off-kilter canvas mirroring both the plot of "Swan Lake" and Nina's descent into what may very well be madness.

"Black Swan" is fascinating it its uncompromising depiction of what goes into ballet dancing (busted toenails and cracking bones are just the tip of the iceberg). Likewise, its cutthroat competitive nature bristles with a claustrophobic coldness that takes the fun out of training, but makes watching it all the more riveting. Screenwriters Mark Heyman, Andres Heinz and John McLaughlin effectively weave a creepy atmosphere into the proceedings, first subtly (Nina swears that she keeps seeing a doppelgänger of herself around the city, and also spots out of the corner of her eye one of her mother's paintings move) and then with violent force. By the final third, grim surrealism takes over, leading to a conclusion that dare not be discussed except to say that it's as wickedly conceived as it is unforgettably original. Even so, there does come the feeling that director Aronofsky does not push things as far as he could have. One sees how the creep factor could have become downright terrifying with a few uninhibited tweaks, its aura of unhinged determination a kaleidoscopic nightmare were the filmmaker to have embraced his genre leanings. Because so much of the film is predicated on what happens at the very end, the whole comes off as more of a crafty exercise than the more down-to-earth human story it begins as.

In a stripped-down cast of supporting characters, all the actors indelibly leave an imprint. Vincent Cassel (2007's "Eastern Promises") perfectly embodies that of tough, unsentimental ballet director Thomas Leroy, talented as an instructor but also just as willing to spit out his students if they are getting a little long in the tooth or don't provide what he's looking for. Mila Kunis (2010's "The Book of Eli") is alluring and appropriately shady as fellow dancer Lily, her intentions left open for interpretation. As the dark swan to Nina's good one, does Lily really care about being friends with Nina, or is it all an elaborate means of stealing ahead herself? As Nina's mother Erica, Barbara Hershey (1998's "A Soldier's Daughter Never Cries") is a frightful villainess, deceptively caring at the onset before her cheery veneer cracks to reveal a horrid, possibly psychotic shrew whose only means of living is through her daughter. Finally, Winona Ryder (2009's "The Informers") bitterly stands on the fringe as Beth MacIntyre, cast aside by a younger, fresher face and sickened by the thought of having to go through the formalities of handing down the gauntlet to a person who basically has stolen her job. Ryder isn't on screen for long, but her tragic character haunts the company even after she's gone.

In a narrative that grows in abstraction the further it presses on, it is difficult to consistently tell reality from mind games. "Black Swan" toys with this confusion so that what might be considered a plot hole in a more straightforward tale instead just comes off as another piece of the deceptive puzzle. Intriguing to a fault—if not always on solid ground about what kind of film it wants to be—the picture is enriched not only by Natalie Portman's tour de force turn, but also by the Tchaikovsky-fueled music score by Clint Mansell (2008's "Definitely, Maybe") and the exquisitely detailed, at times dreamlike, art direction by David Stein (2004's "Eternal Sunshine of the Spotless Mind"). The story of one person's desire to succeed even at the expense of her mental health and everything else she holds dear, "Black Swan" may not sway many viewers toward Nina's career path, but plenty should be flooding theatres afterwards to see the one-of-a-kind art form up close and personal.