Pete's professional and personal lives become more complicated as he struggles to assert power in both. While facing pressure from his wife regarding a new apartment, he further alienates Don and endangers his own position at Sterling Cooper.

Paul hosts a party at his apartment and introduces someone special to his Sterling Cooper colleagues. Peggy visits her family for dinner. Despite a conflict of interest, the Sterling Cooper agency aggressively pursues an airline account and Duck attempts to appeal to the client using an unorthodox approach.

Betty visits her father; Paul's girlfriend tries to convince him to prioritize his duties; Pete's mother disapproves of his and Trudy's idea.

Things quickly become awkward after the two firms merge, Don asserts his dominance over Sylvia, Pete has to deal with his ailing mother, and Bob Benson helps out a sick Joan.

Don is preoccupied with keeping Sylvia's son from being drafted, Peggy has a rat in her apartment, Don and Ted bury the hatchet, Pete has a problem with his mother's new nurse, and Sally makes an accidental discovery about her father.

Don renews his battle with Ted after seeing his relationship with Peggy, Sally interviews at a boarding school, and Pete discovers Bob Benson's background.