Theater director Caden Cotard is mounting a new play. Fresh off of a successful production of Death of a Salesman, he has traded in the suburban blue-hairs and regional theater of Schenectady for the cultured audiences and bright footlights of Broadway. Armed with a MacArthur grant and determined to create a piece of brutal realism and honesty, something into which he can put his whole self, he gathers an ensemble cast into a warehouse in Manhattan's theater district. He directs them in a celebration of the mundane, instructing each to live out their constructed lives in a small mock-up of the city outside. As the city inside the warehouse grows, Caden's own life veers wildly off the tracks. The shadow of his ex-wife Adele, a celebrated painter who left him years ago for Germany's art scene, sneers at him from every corner. Somewhere in Berlin, his daughter Olive is growing up under the questionable guidance of Adele's friend, Maria. He's helplessly driving his marriage to actress Claire into the ground. Sammy Barnathan, the actor Caden has hired to play himself within the play, is a bit too perfect for the part, and is making it difficult for Caden to revive his relationship with the alluringly candid Hazel. Meanwhile, his therapist, Madeline Gravis, is better at plugging her best-seller than she is at counselling him. His second daughter, Ariel, is disabled. And a mysterious condition is systematically shutting down each of his autonomic functions, one by one. As the years rapidly pass, Caden buries himself deeper into his masterpiece. Populating the cast and crew with doppelgangers, he steadily blurs the line between the world of the play and that of his own deteriorating reality. As he pushes the limits of his relationships, both personally and professionally, a change in creative direction arrives in Millicent Weems, a celebrated theater actress who may offer Caden the break he needs.