Black swan is a film about ballet dancer Nina Sayer played by Natalie Potman who succumbs to madness after being unable to cope up with the pressure coming from her job. Nina struggles to maintain the lead as a ballet dancer and also tries not to loose her self in the process. Barbara Hershy who goes by the name Erica takes the role of Nina’s mother a former barelina who pushes her daughter to the wall by dictating her every move and expecting nothing but the best from her.
Nina’s life takes a whole new dimension when Thomas Leroy (Vincent Cassel) director of New York ballet company decides to start a fresh for the production of the coming season of "swan lake" that involved searching. Nina is chosen as a new lead which takes her by surprise. This required her to play two roles which were namely: the role of the white swan and the role of the black swan.
Due to Nina’s timid and innocent personality she is able to play the role of white swan perfectly, but on the hand she is unable to bring out the role of black swan. Mila Kuna who plays lily takes the role of the black swan and does it perfectly. Nina and Lily start competing with each other which turns their rivalry to a twisted friendship. In order to fit perfectly for the production, Nina tries to get in touch with her dark side.
On this movie Thomas Leroy manages to convince Nina to seek her darker and sensual side in order to be able to play both roles of white swan and black swan with the help of Lily Nina he starts to discover her dark side. Her inner sense and purity are quickly destroyed as her dark side takes over. After this breakthrough Nina starts dancing on the edge as she succumbs to madness unable to handle herself and her career Nina is consumed by ballet and she slowly looses herself in the process.