Black Swan is a 2010 American psychological horror film directed by Darren Aronofsky. The screenplay was written by Mark Heyman, John McLaughlin, and Andres Heinz, based on an original story by Heinz. The film stars Natalie Portman, Vincent Cassel, Mila Kunis, Barbara Hershey, and Winona Ryder. The plot revolves around a production of Tchaikovsky's Swan Lake ballet by the New York City Ballet company. The production requires a ballerina to play the innocent and fragile White Swan, for which the committed dancer Nina (Portman) is a perfect fit, as well as the dark and sensual Black Swan, which are qualities better embodied by the new rival Lily (Kunis). Nina is overwhelmed by a feeling of immense pressure when she finds herself competing for the part, causing her to lose her tenuous grip on reality and descend into madness.