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.

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.