In New York City, a news report is broadcast informing the world that a mission to stop an incoming asteroid has failed and that the asteroid will make impact in three weeks, destroying all life on Earth. Dodge Petersen (Steve Carell) and his wife, Linda (Nancy Carell), listen to the broadcast from the side of the road. When Dodge makes an uninterested response, Linda looks at him in disgust and flees the vehicle without a word.
While everyone around him reacts differently to the news, from suicide to constant drugs and guilt-free sex, Dodge’s life does not change at all. He continues to attend to his meaningless job as an insurance salesman and to employ his cleaning lady and spends his nights alone.
Dodge hesitantly attends the wild party of his neighbors, Warren (Rob Corddry) and his wife, Diane (Connie Britton), where he declines offers of sex and drugs and listens to a philosophical rant from his drunken friend Roache (Patton Oswalt). Dodge shortly returns home to reminisce about his high school sweetheart, Olivia, when he notices his neighbor Penny (Keira Knightley) crying on the fire escape. She has just broken up with her boyfriend, Owen, (Adam Brody) for making her miss her last opportunity to see her family in England. At her apartment, Penny gives Dodge three months worth of his mail that was incorrectly delivered to her and, in the process, unwittingly tells him that his wife was having an affair.