Sara Goldfarb, a widowed television addict, lives alone in a Brighton Beach apartment. Haunted by loneliness and a desire to lose weight, she becomes obsessed with appearing on her favorite game show, prompting her to pursue an extreme diet. As her world starts to revolve increasingly around diet pills, her mental state deteriorates, leading her to experience vibrant but disorienting hallucinations. Meanwhile, her son Harry, his girlfriend Marion, and his friend Tyrone are caught in the grip of heroin addiction. They share dreams of escaping their dire circumstances and achieving a life of luxury and ease. In pursuit of this dream, the three hatch a plan to capitalize on the city's drug trade.

As Sara's fixation deepens, her grasp on reality slips further away, paralleling the downward spiral of her son and his friends. The trio's initial success in the drug world quickly dissipates as supply dwindles in New York, exacerbating their addiction and desperation. With their aspirations crumbling, Harry, Marion, and Tyrone are driven to extreme measures to secure their next fix. The individual quests for their dreams lead them down harrowing paths that test the limits of their endurance and humanity, as addiction strips away their control and exposes the fragility of their ambitions.