It's Valentine's Day, 1962, and the Sterling Cooper advertising agency is hustling to stay on top of its game and buzzing over the newest office equipment. Don and Duck find themselves at odds over an account. Betty reconnects with an old friend and once again finds herself struggling with car trouble.
A plane crash causes the firm to go after the account for the airline involved and drop the smaller airline they have an account with. Paul hosts a party at his apartment and introduces someone special to his Sterling Cooper colleagues. Peggy pays a visit to her mother and sister, who are now guardians of a child.
Problems surface on the set of a commercial shoot while Don plays hooky from the office. The ever-ambitious, career-minded Harry musters support for a sponsorship plagued by controversy. Betty steps in to help Don when he arranges a dinner to placate his upset clients.
A last minute pitch meeting has Sterling Cooper staffers working double time in preparation. Peggy's family hosts lunch for their church's new priest and Don and Betty have a family weekend together.
Joan might have found Don a perfect secretary but Don finds himself in the middle of personal issues between a TV comedian and the man's wife.
Don and Duck attempt to make peace at the office while Peggy tries to find a way to participate in the high-level after-hours meetings being held by the executives. Also, Duck receives a family visit at the office.
Don steps up in class and purchases a new set of wheels that is more appropriate for a big-time executive. Pete, Harry and Ken come up with a plan to attract new business and Don's secretary makes a serious error, which could mean trouble for Joan.
Betty becomes suspicious that Don is having an affair after her conversation with Jimmy Barrett, Joan helps out in the television department, and Peggy helps the church with a dance flyer.
Don checks in to a hotel after his separation from Betty. Back at the office, he is forced to get rid of Freddy against his will because of his drinking problem.
Don and Betty try to keep up appearances as they go to Betty's parents after her dad has a stroke. Peter has a long-dreaded meeting with his mother before he and Kinsey leave for a convention in Los Angeles.
Don blows off the convention in Los Angeles when he meets a beautiful, exotic woman. Back at Sterling Cooper, a member of the creative staff comes out of the closet, and Duck falls off the wagon and initiates his power play.
An old friend and Don renew their acquaintance. Pete's personal problems impact a major account. Joan introduces her fiancé around the office. Bert and Roger consider the merger offer and Peggy makes a play for a real office.
While the Cuban Missile Crisis looms, things at Sterling Cooper don't run as smoothly while Don is away. Betty receives some upsetting news.