Season synopsis
Contains spoilers for this season and earlier seasons.
Sterling Cooper Draper Pryce begins as a cramped, underfunded start-up, with Don living alone after his divorce and trying to keep work and family at arm's length. He drinks heavily, dates casually and struggles with the question of who he is without the old office and country house. Peggy takes on more responsibility and begins building a life beyond the agency, while Pete and Trudy welcome a daughter. Joan keeps the office running as Greg leaves for military service, though her marriage offers little comfort.
Don learns in California that Anna Draper has terminal cancer; after her death, Peggy comforts him, and he begins dating consultant Faye Miller. At the agency, Lucky Strike's departure threatens SCDP's survival, and Roger has concealed how long he knew it was coming. Joan becomes pregnant after sleeping with Roger and decides to continue the pregnancy, letting Greg believe the baby is his. Don responds with a full-page New York Times ad declaring that SCDP will no longer take tobacco clients.
The firm is still scrambling for business when Peggy and Ken land Topaz pantyhose and Don takes his children to California to settle Anna's affairs. At Anna's old house, Sally notices a message addressed to Dick, forcing Don to acknowledge that name to his daughter. Don is moved by Megan's ease with his children during the trip, and he tells her he loves her and proposes. Megan accepts, while Faye, who had been dating Don, learns that he has chosen someone else. The season ends with SCDP still uncertain and Don suddenly engaged.