photo Most of us will never know what it’s like to crawl into another skin. It’s hard enough being in our own. Movies, however, are designed to illuminate the human condition—all conditions—and beg us to open our minds to the experience of another person, in order to, hopefully, gain a better knowledge of those around us. It’s a temporary putting on of another life, one we can watch/live through for two hours and then leave behind, along with our empty popcorn bucket and candy wrappers.

Some are harder to let go of than others.

I knew exactly what I was getting when I bought my ticket to see Shame. The first thing you know about it is its rating: NC-17 (the rating that replaced X in 1990), widely regarded as the kiss of death in Hollywood. The second thing you know is it stars two of the hottest actors in Hollywood right now, Michael Fassbender and Carey Mulligan. Surprisingly, there was a film that flirted with an NC-17 rating just last year, also starring two hot young actors, Ryan Gosling and Michelle Williams in Blue Valentine. That movie, however, was able to make some minor cuts and was successfully released with the more box-office (and Academy)-friendly R rating.

There will be no such luck for Shame. Cutting Shame to get an R rating would leave no movie left.

So, if you can bear a movie that bares it all, Shame will reward you with an absolutely devastating experience that will linger long after the lights come up. No, that’s not a bad thing.

If you don’t know who Michael Fassbender is, I don’t know if I would recommend this to be your first experience with him. He is a marvelous actor who, just this year, has played everything from Rochester in Jane Eyre to Magneto in X-Men: First Class to Carl Jung in A Dangerous Method. But it is his performance here as Brandon, a sex addict, that is his crowning achievement and (should) quite possibly nail down an Oscar nomination for Best Actor. And for that to happen in a movie rated NC-17 would be virtually unheard of. He’s that good.

But it’s hard to call anything that has to do with this movie good. It is a tragic story of a tragic character with no hope of redemption or salvation. It is a portrait of a man who is nothing but an empty shell of a human being, someone whose only ability to relate to the world is through random sexual encounters, and even these leave him hollow and desperate only for more, even though nothing can and will ever satisfy him. We’ve seen stories about addicts before, but never before have we seen this kind of addiction—the kind that craves human contact when the last thing they are actually able to do is connect with another human being.

Shame doesn’t try to be anything other than what it sets out to be: a portrait. And portraits like this only work when the actor is up to the task of enveloping himself in the skin of the character, going for broke and holding nothing back. Fassbender is an actor who pours himself in and lets himself drown in the character and his performance here is staggering in its despair.

Equally up to the task of laying bare (literally and figuratively) is Mulligan, one of my favorite actresses, who plays Brandon’s flighty sister, Sissy. The relationship between Brandon and Sissy seems to be complicated and weighed down by a backstory that we never learn, and their interactions are both difficult and perplexing to watch. This is Fassbender’s show, but Mulligan stays with him, note for note, and continues to prove her enormous talent.

But Shame is all about Michael Fassbender. He and director Steve McQueen, who also directed Fassbender in Hunger, another film that required the actor to give it all (the already-skinny actor shed 30 pounds to play IRA hunger striker Bobby Sands), seem to have a working relationship based on trust, for it is rare to see an actor bare his soul as much—and as well—as Fassbender does here. The moments when you really get what a hollow shell Brandon is are nothing short of heartbreaking and McQueen guides Fassbender to a performance that is as tragic as it is powerful.

Let’s not mince words here: Shame is a difficult movie to sit through. It is slow-paced, doesn’t have much of a plot and is the furthest thing from sexy, despite all the graphic nudity and sex acts portrayed on screen. It is depressing and desperate, there’s no getting around it. But if you are a fan of acting at its highest level, this is a must-see. I just wouldn’t recommend it for a first date.