Don has difficulty adjusting to being the public face of his new company, while Betty and the children endure an uncomfortable dinner with Henry's family.
As the firm throws a Christmas party, Don prepares for his first Christmas away from his children.
Lane and Joan get into a disagreement at the agency and a mix-up with flowers has a hand in Lane's wife staying in London indefinitely. Don leaves for Acapulco with a stopover in Los Angeles. While in LA, Don visits Anna Draper. Once back in New York, Don and Lane get to know each other better on New Year's Eve.
Pete must break bad news to his father-in-law but receives wonderful news about him and Trudy. Don gets into a confrontation with Allison after a focus group. Peggy meets an eccentric girl named Joyce in the building.
Don and Pete try to land a new client but Roger's attitude about the potential client may ruin their chances of showing up their competition. Also, Sally acts out and Betty wonders if therapy is the solution.
Peggy and the new art director do not see eye-to-eye and Peggy goes to interesting extremes to get his attention. A potential new employee reminds Don and Roger of when they first met. Pete is unhappy that Ken may be joining their firm. Also, the agency is up for a CLIO award.
A deadline on the Samsonite account disrupts Don and Peggy's plans on the night of the Ali-Liston fight.
Joan must deal with questionable activities at the office and Peggy's reaction to them makes Joan angry. Also, Betty and Henry run into Don while he is on a date.
Joan and Roger reconnect after a brush with violence. Peggy receives attention from a very opinionated suitor. Also, Don has more trouble with Sally.
After landing a government contract, Don panics when two G-men arrive at Betty's house; Pete faces a moral dilemma; Lane introduces his visiting father to his black girlfriend; Roger juggles Joan's latest abortion with bad news from Lucky Strike.
All employees of Sterling Cooper Draper Pryce are called in for a meeting and speculation and gossip starts to fly around the office.
The agency scrambles to lure new clients and Don makes a risky move in the hopes that it will help them all. Later, Don runs into an old friend, Midge. Also, Sally comes to a realization in therapy.
Peggy and Ken land a new client for the firm. Joan gets promoted and shares a secret with her husband. Don takes the kids with him to California and faces a life-altering decision.