Note to Moms out there: if you would like to discourage your little girl from becoming a ballerina, this is the movie to have her watch. It's the bearded-Spock universe's version of The Red Shoes. Your daughter won't want to dance. She will be frightened by swans. In fact, she will become catatonic if she gets too near the Swan Boats in the Public Garden in Boston.
Natalie Portman plays Nina, who's eager to climb to the top of the ballet world, playing (both) the White and Black Swans in Swan Lake, staged by a Big Important New York Ballet Company. She successfully displaces the older star (played by Winona Ryder), who doesn't take it well. Nina's director (Vincent Cassel) drives her mercilessly. She suspects another dancer (Mila Kunis) is trying to horn in on her role. Her mother (Barbara Hershey) is a has-been (and never-was) dancer herself, and she's a manipulative lunatic.
And then things gets kind of creepy: Nina starts hallucinating she gets paranoid, she hangs out with the wrong kind of people, ingests some ill-advised of substances, and otherwise neglects the USDA nutrition pyramid. Things go badly.
This movie won Natalie Portman a Best Actress Oscar, and got four other Oscar nominations, including Best Picture. So I'm surprised I didn't like it better; I think I was put off by the creepiness and ambiguity. ("I had no idea what was real and what was fantasy!" "It was all fantasy, Paul: it's a movie." "Well, yeah, but…")