Season four takes place between November 1964 and October 1965. It is set at the new and considerably more modern advertising agency, Sterling Cooper Draper Pryce. The main narrative of the fourth season is driven by Don Draper's identity crisis. As Don falls deeper into existential despair, he begins regularly meeting with women of loose moral character and faces debilitating alcoholism.
Don deals with a trade-paper interview but doesn't want to talk about himself. A manufacturer of a "wholesome" two-piece bathing suit wants to hire the firm but doesn't want anything too risque. Pete and Peggy try to secure more money for the firm.
The agency's Christmas party is nearly spoiled by the late arrival of a surprise and not-so-welcome visitor.
Don takes a trip. Joan has scheduling problems. Don and Lane get to know each other a little better.
An edict from Roger and Lane puts Pete in a personal dilemma.
Don and Pete disregard Roger's plans in order to land a new client.
Peggy clashes with her new creative partner; Don pitches under unusual circumstances.
A deadline disrupts Sterling Cooper Draper Pryce.
Joan and Peggy deal with high-jinx in the office.
Peggy is forced to face some unpleasant facts about a client's discriminatory business practices. Don and Faye's burgeoning relationship is tested when Sally runs away from home and turns up at the office. Roger tries to rekindle his affair with Joan.
An unannounced visitor at the Francis home rattles Betty.
Sterling Cooper Draper Price employees resort to scuttlebutt after an agency wide meeting is called.
In the midst of a crisis, Don runs into an old friend.
Don and Peggy are faced with life-altering decisions.