The writers make an attempt to stave off late-night boredom during a mandatory overtime session. Roger throws a party as Joan and Greg host their own party. Sally has a run-in with Grandpa.

The firm celebrates as they hit a milestone. Peggy and Paul compete to secure the same account.

Peggy's taste in men proves questionable. Pete has to make a big decision about his career and a candidate makes a big impression on Don.

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.

While Don continues his affair with Sylvia, Pete's latest infidelity threatens his marriage. Meanwhile, Peggy's icy relationship with her new staff continues, but she also gets an unlikely tip on a potential new client.

Don works in secret on a Heinz ketchup campaign while Megan gets a love scene on the set of her soap opera. Meanwhile, Harry makes his power play while Joan has more trouble with the secretaries.

Set among the events surrounding Martin Luther King's assassination, Peggy tries to get a new apartment, Ginsberg is set up on a date, and Don has a revelation during his weekend with the kids.

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.

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.

The creative department has a wild, drug-influenced weekend as they work on the Chevy account, Don has trouble letting go of Sylvia, and Sally walks in on an unwelcome intruder.

Peggy becomes unsatisfied with her apartment and with Abe, Don has an eventful weekend with Betty while Megan has problems on the set, Roger has time with his grandson, and Pete begins exploring his options outside the firm.

Cutler and Chaough prepare to make radical changes to the firm while Sterling and Draper are visiting a client in Los Angeles. Joan's decision to go after a new account on her own leaves Pete furious and frustrated.

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.

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 makes a new friend. Joan meets a client for drinks. Peggy hears impressive new work. Roger has a puzzling phone call.

Peggy receives a bouquet of flowers at the office. Pete navigates the politics of new business. Joan is put in an impossibly awkward situation.

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 has a visitor from his past. Stan embarrasses a superior. Peggy helps Ginsberg with a problem. Harry finds that he has a new ally at the agency.

Peggy determinedly collects research for a pitch. Pete is invited to join an exclusive club. Joan looks forward to spending time with her friend.

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.

Don attempts to track down a friend, Joan tries to solve a problem with an account and an unlikely person sets up Peggy.

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

Roger pawns off a project on Don, Joan goes on a business trip and Peggy and Pete cannot agree on how to deal with an account.

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.

Don receives a reward for his work. Joan butts heads with her co-worker on an account. Faced with a big decision, Roger dodges.

Don has trouble sleeping. Pete is blindsided by a difficult friend. Facing a new challenge, Henry arranges a family reunion.

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