Season synopsis
Contains spoilers for this season and earlier seasons.
Don’s marriage to Megan and his work both begin to unravel. On a Hawaii trip tied to SCDP’s Sheraton account, he meets a soldier whose lighter he later keeps by mistake; back in New York, Don begins an affair with neighbour Sylvia Rosen, whose husband Arnold is a doctor. He drinks heavily and neglects his children. Sally discovers him with Sylvia, while Peggy, now at rival agency Cutler Gleason Chaough, grows into a leadership role. Pete’s suburban marriage to Trudy also breaks after he has another affair.
The country’s grief enters the office after Martin Luther King Jr. is assassinated, and later the staff watches news of Robert Kennedy’s killing. Meanwhile, a General Motors pitch brings SCDP and CGC into a merger, creating Sterling Cooper & Partners. Don and Ted appoint Peggy copy chief, but Don’s rivalry with Ted and Ted’s feelings for her strain the new partnership. Pete investigates Bob Benson and learns that he fabricated his work history; he keeps the secret as leverage, then loses control of Chevy after Bob exposes Pete’s poor driving in front of the executives.
Don’s drinking and impulsive choices worsen. At a Hershey meeting, he abandons his polished pitch and tells the executives that a chocolate bar was a rare childhood treat amid life in a brothel; he says Hershey does not need advertising. The partners place him on leave, with Lou Avery acting as creative head. Ted moves to California, Peggy takes Don’s office, and Megan leaves him. Don then takes his children to see the rundown house where he grew up.