Don continues to conceal his complicated personal life, even in the face of Roger's invitation to open up.

Pete returns home from his honeymoon excited about his new marriage but conflicted about his past encounter with Peggy.

Don Draper is shaken when his past life comes back to haunt him. After his picture appears in a local newspaper, Adam Whitman, a man who claims to be his younger brother, approaches him. Don, or Dick as his brother knows him, initially denies everything but in the end admits to having taken on a new name. He refuses however to have anything to do with him and tries to buy his silence. When one of the ad men gets a short story published, Pete Campbell is frustrated that his own stories have yet to see the light of day. When his wife approaches an old beau to see if he will publish the stories, he has an interesting proposition for her.

When Don invites Roger home for dinner, too much alcohol fuels repercussions between Don and Betty and between Don and Roger. Joan puts Roger off for the weekend, spending time with her roommate Carol instead. Pete exchanges a wedding gift for a rifle, and then shares a hunting fantasy with Peggy. Bertram Cooper arranges for the Nixon campaign to meet with him, Roger, Don, and Pete.

Don is courted by Jim Hobart, head of a larger ad firm who offers him more money and more creative resources to join them. Betty Draper rekindles her interest in modeling after Hobart suggests she should try it. She doesn't realize it's all part of the strategy to get Don on board. Peggy Olsen is fretting over her weight gain but doesn't appreciate Joan's advice about getting ahead in the office. The ad team tries to counter the advertising coming out of the Kennedy campaign. Pete Campbell comes up with an idea to keep Kennedy's image off TV in key States.

Peggy is given the opportunity to write copy for a new weight loss device that everyone knows is useless. She finds an interesting use for it, however. Afraid of losing the Lucky Strike cigarette account, Bert Cooper gets Roger Sterling to come in for a one-hour meeting but he has another attack. Don Draper becomes a partner and takes over for his friend Roger, but some of the ad men are sharpening their resumes nonetheless. Pete Campbell wants a promotion but Draper doesn't seem too interested. Pete sneaks into Don's office and takes home a parcel sent by Adam addressed to Don that the mail room boy comes to deliver.

Don and Betty Draper have an argument when it becomes apparent that he doesn't want to spend Thanksgiving with her family and she plans on going only with the children. He also learns some information about his brother Adam. Pete Campbell confirms that he has landed an account from his father-in-law for a new skin care product called Clearasil. He objects however when Don gives the account to Peggy Olson, whom he has just promoted to junior copywriter. Peggy proves her mettle in auditions for the weight loss device but later is feeling unwell and goes to the hospital where she is given some shocking news. Don comes up with a brilliant presentation for Kodak on a new wheel-like storage device for a slide projector that he dubs The Carousel.

On Valentine's Day, the staff of the Sterling Cooper Advertising Agency is hustling and checking out the newest office equipment. Don and Duck clash over an account, and Betty hears from an old friend.

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. Peggy pays a visit to her mother and sister, who are now guardians of a child.

Under the backdrop of the Cuban Missile Crisis, Don returns to New York just as Betty finds out that she is pregnant. Meanwhile, everybody at Sterling Cooper contemplates their futures as news of the merger slowly leaks out.

Betty has hallucinations of her deceased father as she delivers her baby, Peter considers trying to sell the untapped "Negro market" to a reluctant client, and Peggy begins to question her future at Sterling Cooper.

As Don secures an account with Conrad Hilton, Sterling and Cooper try to strong-arm Don into signing a contract. Meanwhile, Betty meets with her acquaintance from the governor's office, and Duck tries to get Peggy to leave Sterling Cooper.

Don and Betty renew their love affair while on a business trip to Rome, while Peter has a bout of infidelity with an au pair in his building while his wife is away.

Betty tries to meet with Henry Francis again, while Don steps up his pursuit of his daughter's former teacher. At the office, Don disappoints Conrad Hilton and is forced by a client to fire Salvatore over an unwelcome advance.

While Don's thoughts turn inward while he deals with Anna's death, Peggy is placed in a difficult situation when an obnoxious employee in the creative department is disrespectful to Joan.

After a fight with Megan during a surprise trip to California, Don decides it's time to get back to work. Meanwhile, Betty joins Bobby on a field trip to a farm.