Peggy's co-workers are bothered when she's given a new job opportunity. Don's work gets in the way of his home life. Betty uncovers a shocking secret.

The staff at Sterling Cooper pull an all nighter as they watch the Nixon-Kennedy election returns. Also, Pete's ambitions cause him to directly challenge Don.

While Peggy gets assigned to a difficult project, Don grabs ahold of an opportunity provided by Roger's latest work problems. Pete has more problems at home and at the office. Betty's frustrations lead her to seek some new relief.

Don loses an important account and Roger, who happens to be stuck in the city on Labor Day, attempts to cheer him up. Meanwhile, Joan and her roommate go out to paint the town.

Betty is used by a rival ad agency to try to hire Don. Peggy is sought after by two romantic rivals. The agency tries to spruce up their Nixon presidential campaign endeavoring to counteract a successful Kennedy ad.

Don's past comes back to haunt him; success becomes a problem for Peggy's relationship with her co-workers; Salvatore bonds with a client.

When Roger and Don hit the town together Roger's behavior puts a strain on their relationship.

Rumors spread in the office about a surprise romantic affair. Peggy's ideas get noticed during a pitch meeting and her future at the agency begins to look more promising. Don asks Rachel's advice about an ad campaign.

Don's past catches up to him when he wins an award and gets his picture on a prominent industry periodical. Ken makes his colleagues jealous when he gets a short story published in a national monthly magazine.

Don teaches Pete a lesson when he oversteps his authority in dealing with a valuable client. At home, Pete is pressured from his newlywed bride to buy their own apartment unit.

Upon returning from his honeymoon, Pete is troubled by what happened with Peggy at his bachelor party. Don's professional relationship with Rachel undergoes significant changes.

Betty consults with a specialist about her health issues; Don is pressured to help with Nixon's presidential campaign; Peggy fends off the coming advances of one of the copy writers.

While Don struggles to control his problematic love life, he tries to keep the agency from losing a big tobacco account.