Worried about the transience of his life, theatre director Caden Cotard (Philip Seymour Hoffman) leaves his home behind and sets out to construct a massive artistic enterprise. Gathering an ensemble cast into a warehouse in New York City, he hopes to create a work of brutal honesty. He directs them in a celebration of the mundane, instructing each to live out their constructed lives in a growing mockup of the city outside. The years rapidly fold into each other, and Caden buries himself deeper into his masterpiece but the textured tangle of real and theatrical relationships blurs the line between the world of the play and that of Caden's own deteriorating reality.