Called "this year's dirty movie" by The New York Times, Shame has taken over for last year's Blue Valentine as the film that makes even the most sexually comfortable viewer a little uncomfortable.

Shame, directed by British artist-turned-filmmaker Steve McQueen, tells the story of Brandon (Michael Fassbender), a smooth-talking, handsome sex addict who lives and works in New York. Brandon lives alone in an apartment devoid of characters, spending his days in a male-dominated corporate job and his nights in the arms of a blur of sexual partners. The catalyst for the movie's plot comes with the arrival of Sissy (Carey Mulligan), Brandon's younger sister with a history of self-abuse and drug dependency, who wastes no time before seducing one of Brandon's co-workers and bringing him back to Brandon's apartment (and his bed).

Like any movie with a focus on addiction, the film struggles with the portrayal of its characters as people versus sufferers. Unlike other "addiction movies," however, Shame focuses not on a bottle or a needle but on sex. Society tends to both ignore and shame sex addiction, a condition that is publicly invisible and is regarded more often as an excuse for marital infidelity (Tiger Woods, anyone?) than a legitimate mental and physical addiction. Fassbender's portrayal of Brandon lends itself brilliantly to the legitimization of sex as an addiction, rather than a mere act of passion or pleasure. The movie's many sex scenes are brutal and unromantic, calling to mind images of an alcoholic on a binge or a heroin addict shooting up—Brandon is killing an urge for a fix.

The topic of sex addiction adds another layer of challenge for the filmmaker. As Blue Valentine proved last year, there are a number of rules and conventions that place limits on how explicit on-screen sex can be before the movie is not only limited in its accessibility to viewers by distributors, but also causes excessive discomfort for moviegoers, even in a movie rated NC-17. Yet discomfort seems to be McQueen's intention. The lighting and cinematography in his sex scenes call to mind eroticism, but Brandon's facial expressions are almost pained, the quintessential pleasure-pain mix described so often by addicts. While watching an on-screen character take a shot of whiskey or shoot up won't get a viewer drunk or high, however, explicit on-screen sex can have both physical and psychological effects on many viewers. Considering the myriad social and emotional conceptions around sex, McQueen's directorial choices regarding the more explicit scenes are brilliantly twisted, provoking confusion, intoxication and despair all at once.

If McQueen's directing was twisted, Fassbender's performance as Brandon was even more so. This is Fassbender's second sex-related film of the year; the role of Brandon comes after his portrayal of Carl Jung in A Dangerous Method. Yet while both characters were men of hefty sexual appetite, Brandon's addiction to sex is graceless and harsh in comparison to Jung's more clinical approach. Fassbender has a deep command of his body language, even (or perhaps especially) in sex scenes, and his incredibly expressive face reveals the sort of internal conflict that seems more suited to novels than film.

Complementing Fassbender's Brandon is Carey Mulligan as Sissy. Her emotional attachment and sloppiness pose a sharp contrast to Brandon's distance and self-control. The relationship between the two siblings is bitter, angry and sometimes violent, but elegantly portrayed. They seem to be showing opposite reactions to some implied deep-seated trauma, though what this trauma is is open to interpretation by the audience. "We're not bad people," Sissy says tearfully in a message left on Brandon's cell phone. "We just come from a bad place."

Visually, Shame is stunning. McQueen is first and foremost a visual artist, and that shines through brilliantly in the way he portrays not only his actors but the scenery, from Manhattan skylines to dimly lit bedrooms. His cinematography is subtle and complements the actors' movements and interactions beautifully.

While Shame is clearly a movie about addiction, I hesitate to call it an "addiction movie." It is much more of a character film—presenting Brandon for our study, titillation, judgment and maybe even envy—but stops short of provoking our sympathy. The film asks whether "shame" is something Brandon feels or just what the audience, in our own conceptions around sex and addiction, projects onto him.