Pete Campbell and Peggy Olson start an office romance. Peggy's copy for the lipstick account goes over well and the men in the firm congratulate her. A new telephone receptionist, Lois Saddler, takes a liking to Salvatore Romano but his own interests seem to lie elsewhere. Don Draper gets an unexpected bonus from Bert Cooper and wants to take Midge on a surprise trip to Paris. She seems too involved with her beatnik friends however. Don reflects on his unhappy childhood and in flashbacks he reveals some life lessons he learned early on when a hobo spent the day working on the family farm in exchange for a meal.

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.

Trouble rises on the set of a commercial while Don plays hooky from the office.

Freddy and Ken take a client out to lunch who stirs Roger Sterling's heart.

Joan finds Don the perfect secretary, and Don finds himself in the middle of issues between TV comedian Jimmy and his wife, Bobbie.

Don and Duck try to bury the hatchet, and Peggy attempts to join in on the execs' after-hours meetings. Also, Duck receives a family visit at the office.

To show that he has "arrived," Don buys a new car. 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. Cooper gets a new piece of office art that attracts the interest of the Sterling Cooper staff.

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 drops off the Sterling Cooper radar and visits the wife of the man whose identity he stole. Back at the office, Bert and Roger consider the merger offer, Peggy makes a play for a real office, and Peter loses his father-in-law's account.

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.