A young, talented ballerina, Nina Sayers, secures the lead role in a New York City ballet company's production of Tchaikovsky's "Swan Lake." She is perfect for the role of the delicate White Swan, but she finds herself struggling with the darker aspects of the Black Swan. The company's demanding and seductive artistic director pushes Nina to tap into her sensual side to embody the dual role effectively. Her innocence and technical precision align with the White Swan, yet the Black Swan requires a seductive malevolence that does not come naturally to her.

As rehearsal intensity increases, Nina becomes increasingly obsessed with perfecting her performance. She faces competition from a new dancer whose uninhibited approach embodies the Black Swan effortlessly, causing Nina to spiral into a web of paranoia and confusion. The pressure mounts, exacerbating Nina's psychological state, blurring the lines between her life and the character she plays. Her journey to artistic perfection takes a toll as her quest forces her to confront her inner demons and reevaluate her own identity in her pursuit of artistic brilliance.