Some movies are hard to watch and Black Swan proves that Darren Aronofsky is one of the best directors making those kind of movies. The film shows the psychological impact suffered by ballet dancer Nina Sayers (Natalie Portman) as she prepares for the role of Swan Queen, a combination of both the "White Swan" and its polar opposite the "Black Swan", during a production of Swan Lake. It's at this production she meets Lily, a fellow company dancer played by Mila Kunis, whose impulsive and free-flowing approach to dancing contrasts with Nina's frigid and methodical style. Nina's dancing style prevents her from performing the Black Swan character to the degree she always strives for: perfection. The disparity between her personality and the one the role she's playing requires is the gravity that fuels her descent into madness.
This descent into madness is terrifically handled by Aronofsky who, using slick CGI, perfectly creates the illusion of real life and projections of Nina's subconscious blending together. Thanks to this illusion, you find yourself questioning how much of what you're seeing is real and how much is Nina's mind playing tricks on her. Much like in Aronofsky's emotional rollercoaster Requiem for a Dream, some of these hallucinations explicitly show blood and other types of physical damage which really add depth and realism.
As good as the direction is, a major thumbs up is due to the whole cast. Natalie Portman has one of the most demanding parts she will ever have to do and she rises up to the challenge perfectly, creating and developing two parallel characters: Nina and the "Swan Queen." Mila Kunis is also good as she has to play a character that flip-flops back and forth between pleasant to treacherous. My only complaint is that some of her lines were a bit too humorous and felt like they were penned by a sitcom writer. The final actor, who in my opinion isn't getting the praise he deserves, is Vincent Cassel who plays Thomas Leroy, the production director. The way he commands the screen is mesmerizing, it really feels like he's a real director and he's in control of everything involved, and uses this control to make sure his vision of the ballet is the finished product.