The affluent Taylor clan gathers for the 25th wedding anniversary of liberal
Georgetown professor Ellen and restaurateur Paul. Attending are their four children: Cynthia, an environmental lawyer like her husband Rob; Anna, a caustic lesbian comic; the teenager Birdie, a bohemian would-be wildlife scientist; and Josh, an unsuccessful novelist – and his poised fiancée Liz Nettles, who practices greetings in a mirror before meeting the family. Liz is polite, but Ellen realizes she was a student who left Georgetown after Ellen challenged her
totalitarian ideas in a paper advocating a
one-party state. Liz shocks Ellen by gifting her new book, written with Josh's help,
The Change: The New Social Contract, the cover showing an American flag with the stars placed at the center, supposedly to represent Americans uniting in the
political center. Leaving, Liz tells Ellen privately that she is not afraid of Ellen anymore. Two years later,
The Change has become hugely influential; at the Taylors' Thanksgiving gathering, Anna's assistant/lover says it helped her reconnect to her parents. Liz is now pregnant with twins, and Josh, now with a
makeover, has grown more confident, even arrogant. However, the four Taylor women are not enthusiastic about Liz or the book, which is sponsored by the Cumberland Corporation. Liz gives Birdie a password to a noted
virology database. Shortly after, a video of Ellen vandalizing a neighbor's "Change" American flag goes
viral. In the confrontational atmosphere, Liz first feels sick, then appears to break water and go to the hospital, though later, it seems she only urinated from stress. The following year, Ellen has lost her Georgetown job. A totalitarian "Change" society is in place. Anna, beaten up when making fun of the "Change" movement at a show, is in hiding. Birdie's journalist-student boyfriend Moses drops by, but feels threatened by Josh mentioning
a journalist who was dismembered, and leaves. Liz offers Birdie a job at Cumberland studying virology, which disgusts Ellen, who threatens to kill Liz. Rob joyfully announces that Cynthia is pregnant; however, when they leave, she reveals she had an abortion, fearful of bringing a child into the currently troubled world. Enraged and grieving, Rob drives off and leaves her behind. Josh offers to support Paul's failing restaurant, but Paul suspects he does it to find Anna. Josh and Liz's
au pair Gerda shows Ellen a message from Anna as proof of life. A year later, Rob has joined the "Change". Cynthia, addicted to sleeping pills, lives with her parents. Census-takers ("Enumerators") arrive and ask Ellen and Paul, whose restaurant has closed, questions designed to find Anna, enraging them. The Enumerators show photos of Birdie at a protest, threatening jail; Ellen capitulates and endorses the "Change", angering Birdie, who says Ellen has sold out. The next year, at the Taylors' 30th anniversary party, Liz, dressed in red as Ellen was at the first anniversary, speaks privately to Ellen, asking her to help with Josh's unspecified strange behavior; Ellen slaps her. Liz and Josh then invite Ellen and Paul to dance to a favorite song. While they dance, a clown unexpectedly arrives. The clown enters the house and turns out to be Anna, who speaks to the confused, despondent Cynthia. Josh gets alerted by a partygoer about an attack on Cumberland and enters the house. The television news announces a horrific bio-weapon attack at the Washington, D.C. Cumberland headquarters, where Birdie works; Birdie appears on camera and performs a suicide bombing. Ellen and Paul are devastated, sobbing; Anna joins them. Josh notifies the police of Anna’s whereabouts. Cynthia stabs Josh, though not fatally. She then exits the house with the bloody knife, and police officers open fire. The police also shoot at Anna, who runs from the house and dives into the sea. The police enter the house and put bags over Ellen's and Paul's heads; Paul tries to soothe Ellen by reminding her of when he first met Ellen, in front of
René Magritte's
The Lovers painting, which shows lovers with cloth-covered heads. Josh asks a policeman to keep his parents together, but the police ignore him and wrestle him to the ground. A policeman asks Liz what to do; she says that Josh is with his parents. The police remove the Taylors. Liz, having destroyed the Taylor family, looks at a picture of them in happier days; she looks distraught, but her reverie is interrupted by a small smile. ==Cast==