The agency's Christmas party is nearly spoiled by the late arrival of a surprise and not-so-welcome visitor.

An edict from Roger and Lane puts Pete in a personal dilemma.

Peggy clashes with her new creative partner; Don pitches under unusual circumstances.

Peggy is forced to face some unpleasant facts about a client's discriminatory business practices. Don and Faye's burgeoning relationship is tested when Sally runs away from home and turns up at the office. Roger tries to rekindle his affair with Joan.

An unannounced visitor at the Francis home rattles Betty.

For the Draper family, life has changed. The children must adapt to a new home, a new brother, and a new stepmother. Don seems to have everything a man could want. However, Megan, still employed at the agency, has difficulty interpreting Don's expectations for a sex kitten at home and a prim and proper employee at the office.

Don and Megan work out some of their issues, Roger and Pete butt heads, and Joan has a run-in with a house guest.

Harry finds himself in an uncomfortable position after reconnecting with Paul Kinsey who has joined the Hare Krishnas. Lane takes drastic and unethical measures to get out of financial trouble. Don spends an afternoon with Joan to get her mind off her marital problems.

Pete asks Joan to make a personal and moral sacrifice to ensure the company lands the Jaguar account. Don becomes furious after learning of the impact Megan's new profession will have on their life. Feeling unappreciated, Peggy attends lunch with Freddy Rumsen, who encourages her to make a move.

Don and Megan take a trip to Hawaii for the holidays, Sally's friend visits the Francis family, a comedian torpedoes Peggy's Super Bowl ad campaign, and Roger gets some bad news about his mother.

Don strikes up a friendship with the surgeon in his building, Peggy tries to save her campaign, Roger makes a scene at his mother's funeral, and Betty goes to Manhattan to find Sally's friend.

As the firm prepares to go public, Don and Pete's actions cause them to lose two huge clients. However, Roger uses a new connection to put them in position to gain their biggest client ever.

With his personal and professional life crumbling around him, Don positions himself for a change of scenery. Meanwhile, Pete's life is falling apart as well, thanks to the meddling of Bob Benson.

Don takes an impromptu trip. Betty has lunch with a friend. Harry lobbies for a cause. The partners consider a questionable asset.

Sterling Cooper & Partners prepares for a guest; Don contacts an old friend; Roger deals with problems at home; Peggy is underestimated.

Don receives a troubling letter. A risky venture entails a new future for Peggy. Roger gets an unexpected phone call. Pete butts heads with Cutler.

Roger gives Don some unwanted advice. Peggy and Stan disagree over an account's personnel. Harry asks for Don's blessing.

Don comes up with a big idea, Roger asks Joan to help him fix a clerical error and Peggy has difficulties casting for a commercial.

The stories of Don Draper, his family and his co-workers at Sterling Cooper & Partners conclude.