Jack (Daniel Day-Lewis) and his 16-year-old daughter Rose (Camilla Belle) live in paradisical isolation on a beautiful island off the East Coast of the United States. Rose has been completely sheltered, educated, and created by her father. As he puts it, “Decline and rot, my Angel. That’s the way of the world. Except for you. You are exempt.” But when Jack begins to fear he’s falling in love with his own daughter, he invites his mainland girlfriend (Catherine Keener) and her two teenage sons (Paul Dano, Ryan McDonald) to live with them as family. Rose’s first exposure to society—and sexuality—ignites a psychological combustion that Jack is unable to control.
As one of her new step-brothers says to her, “Innocent people are just dangerous, I guess.”