The second season opens with Don butting heads about personnel matters with Duck, who wants "younger creative talent"; the staff is up in the air about its approach to an airline-company account; Betty bumps into a former roommate who has begun a surprising new career; Joan is at a loss about where to put the new copy machine.
Paul throws a party, then throws his work colleagues for a loop when he introduces them to a special guest; Peggy pays a dinner visit to her family; Duck uses an unorthodox approach to land an airline account, which puts the firm on a conflict-of-interest course.
Problems surface on the set of a commercial shoot while Don plays hooky from the office; 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.
Joan might have found Don a perfect secretary; Peggy comes to the rescue when Don finds himself in the middle of personal issues between a TV comedian and the man's wife; Pete and his wife see a fertility specialist to deal with her inability to conceive.
Don and Duck attempt to make peace at the office; Peggy tries to find a way to participate in the high-level after-hours meetings being held by the executives; one of Duck's family members visits his 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 put their heads together to land new accounts; a serious error by Don's secretary could reflect poorly on Joan; the staff reacts to the new objet d'art in Cooper's office.
Father Gill tries to convince Peggy to volunteer her talents to a church project; Duck and Don team to woo a foreign-beer client by marketing to a new demographic; Harry turns to an unlikely source for help when his department is overloaded with work.
Freddy Rumsen strikes out during a pitch meeting with his team; ever-eager Pete seizes a chance to exploit an opportunity at the office; an old friend is the beneficiary of Don's loyalty; Sara Beth proves to be a welcome ally for Betty.
Betty visits her ailing father; Paul's girlfriend, Sheila, advises him about his civic responsibilities; Pete's mother tries to put the kibosh on an important family move that he and Trudy are planning.