Director Darren Aronof­sky performs a psychological pas de deux with composer Pyotr Ilich Tchaikovsky in Black Swan, a fractured, fascinating study of the high-pressure world of big-time New York ballet.

Natalie Portman (who studied ballet in her teens) plays Nina Sayers, a timid but talented ballerina who has sacrificed a normal life in order to make it as a dancer. Her chances for stardom are fading, however, because of age, injury and the constant emergence of young dancers.

The newcomers include Lily (Mila Kunis), who seems to possess the one attribute Nina lacks as a dancer—passion. Nina is technically perfect, but she lacks fire, or at least the sort of fire she needs to land the lead in Swan Lake. She is perfect for the role of the placid and distant Snow Queen, her demanding, sometimes cruel director, Thomas Leroy (Vincent Cassel), tells her, but how can she capture the heat of the erotic Black Swan, a role that must be performed in the ballet by the same dancer? Despite his reservations, he gives her the part.