Plot[ edit ] Don Draper has married his secretary Megan Calvet, who throws a surprise birthday party for Don and their co-workers. Don is embarrassed by the party and Megan serenading him in front of his co-workers. Megan who has been promoted to copywriter meanwhile struggles with Don's growing detachment with work, as he is constantly having Megan come in late and leave early to the agency, and her own unfulfilled dream of being an actress.
Don's detachment alienates Peggy, who is being made to train Megan, and Bert, who feels that Don has gone "on love leave", not caring about his job or turning in quality work. Feeling her chances at work have been undercut by Don's detachment, the couple have a fight while touring a Howard Johnson's hotel.
Don leaves Megan behind in a huff when she tells him that she's come to find the advertising industry hollow and superficial. Megan manages to hitch a ride back to their new apartment, where they fight and ultimately reconcile. Don's slacking at work coincides with the arrival of a new hire, in the form of young advertising phenom Michael Ginsberg.
Young, aggressive, and anti-social, Ginsberg proves to be a rival for Don and Peggy. When the two are made to pitch advertisements for a snow cone company, Don purposely leaves behind Ginsberg's child-friendly campaign material in order to pitch his own darker, devil-themed campaign instead, which is ultimately chosen. Meanwhile, Peggy finds herself reaching a glass ceiling with regards to Ginsberg being able to rise faster within the company.
However, one evening Ginsberg confides his dark secret to Peggy: By the end, Peggy decides to leave the agency for another firm in order to fulfill her full potential. Don attempts to keep her by offering her a raise but ultimately concedes that Peggy has to leave him to continue out of his shadow. Before she leaves the office forever, Don kisses her hand, finally realizing how important she was to him.
Peggy also makes a new change at home: Elsewhere, Roger struggles to remain relevant in the company as Pete Campbell schemes to steal his plush office for himself. Roger begins to secretly pay Peggy and Ginsberg to produce material for him to pitch to clients.
He also experiments with LSD, which has a profound impact on him and his own marriage to Jane; under the influence of the drug the two confess that their marriage has failed and they divorce. Roger meanwhile begins pursuing an affair with Megan's mother, culminating in Don's daughter Sally catching her step-grandmother performing oral sex on Roger.
Pete Campbell, having moved to the suburbs, begins to become more and more detached from his life and starts missing the big city.
His relationship with Lane Pryce collapses and the two fight, with Lane beating Pete up in front of the other partners. He also begins a relationship with Beth Dawes, the wife of a fellow train commuter, who later breaks off the affair out of guilt even though she and Pete know that her husband is unrepentant in his own adultery.
She later tells Pete that her husband is forcing her to undergo electroshock therapy because of her manic depression. Pete visits his mistress one last time in the hospital, whose memories of the affair have been destroyed. He confronts Beth's husband later on the train, revealing the affair and culminating in a fist fight.
Returning home defeated and alone, his wife Trudy agrees to allow Pete to rent an apartment in the city for overnight stays. Joan struggles with single motherhood while her husband is overseas, with help from her mother. However, when she discovers that Greg has signed up for another tour of duty in the Army Medical Corps without consulting her, Joan confronts Greg and in the process denounces him for his earlier rape of her and orders him out of her and their son's life.
Greg reluctantly agrees but then files for divorce, which upsets Joan as she fears that Greg will paint her as the villain in their divorce case. Further complicating things is the firm's pursuit of Jaguar as a client, as Pete is able to get a promise that the agency will get the account if Joan sleeps with the head of the Jaguar dealers' association.
Pete arranges a vote behind Don's back, and the other partners reluctantly agree to pay Joan to have sex with the executive to secure the account for them. However, Lane convinces Joan to take an ownership percentage of the company instead as Don tries and fails to stop Joan from doing the deed.
The firm wins the account, but alienates Joan and Don from the rest of the partners and from each other. Lane Pryce struggles with his own demons as he is revealed to be greatly in debt and owing a good amount of taxes from when he moved his money to the US last season to help keep the firm afloat.
When his scheme to use his Christmas bonus to pay off his tax debt fails, Lane is forced to steal from the company to pay his debt. Bert and Don discover this and Don fires Lane, who then kills himself rather than face the disgrace of resigning and returning to England. He hangs himself in his office, leaving Roger, Pete, and Don to cut him down. Nobody but Don knows the reason behind his suicide. Megan who has returned to acting seeks Don's help to secure a commercial role for her. Megan's visiting mother cruelly denounces Megan's ambitions and tells Don that he should not help Megan, as she believes that Megan's dream of acting must be crushed and that she should behave like the proper wife of a wealthy man.
While Don is at the dentist, Megan's mother reduces her daughter to a quivering wreck, resulting in Don agreeing to help Megan get the role in order to secure her the happiness she needs to function. Eventually, she gets the role, and after dropping her off at the studio, Don leaves to a bar where he sits by himself and orders a drink. The season ends with a montage of all the main characters having realizations about themselves.
Pete, in the aftermath of his affair with Beth, is seen sitting alone on his couch with his headphones on and eyes closed. Peggy, having quickly risen through the ranks in her new career, is shown toasting a single glass of champagne to herself with a smile on her face. A naked Roger looks out the window of his hotel room at the city, in the throes of an LSD trip, and raises both of his arms into the air. And lastly, Don is seen at the bar, where a woman begins to flirt with him and asks if he is alone.
He turns and looks at her ambiguously.