Betty discovers that she has a tumor, Peggy interviews an obnoxious young copywriter for a job, the firm tries to get the Mohawk Airlines account back, and Don and Harry try to court The Rolling Stones to record a commercial.

Don runs into someone from his past. Joan makes a decision, and Roger gives Peggy extra work.

While Lane needs some help closing with a potential new client, Peter begins to crack under the pressure of both his home life and work life.

A peaceful hotel getaway ends in disaster for Don and Megan, an LSD trip could have a disastrous effect on Roger's marriage, and Peggy loses her cool after an unsuccessful pitch meeting.

Megan convinces Don that she should give up her job at the firm so that she can pursue a career on Broadway, while Peter has a fling with an acquaintance's wife.

Lane searches for a way to get rid of a sizable debt, the firm prepares to pull out all the stops when it gets a second chance to land Jaguar as a client, and Don tries to comfort Joan when she reaches her breaking point.

Peter asks Joan to make an unspeakable sacrifice to help secure the Jaguar account, Peggy prepares to make a drastic move in response to Don's treatment, and Megan's acting career begins to create tension with her and Don.

As the partners consider expanding the office space, Don begins seeing ghosts and gets a request to advance Megan's acting career. Meanwhile, Peter's affair comes to a disappointing end, and Megan's mom briefly reunites with Roger.

Don and Megan take a trip to Hawaii for the holidays, Sally's friend visits the Francis family, a comedian torpedoes Peggy's Super Bowl ad campaign, and Roger gets some bad news about his mother.

Don strikes up a friendship with the surgeon in his building, Peggy tries to save her campaign, Roger makes a scene at his mother's funeral, and Betty goes to Manhattan to find Sally's friend.

Don works in secret on a Heinz ketchup campaign while Megan gets a love scene on the set of her soap opera. Meanwhile, Harry makes his power play while Joan has more trouble with the secretaries.

Set among the events surrounding Martin Luther King's assassination, Peggy tries to get a new apartment, Ginsberg is set up on a date, and Don has a revelation during his weekend with the kids.

The creative department has a wild, drug-influenced weekend as they work on the Chevy account, Don has trouble letting go of Sylvia, and Sally walks in on an unwelcome intruder.

Cutler and Chaough prepare to make radical changes to the firm while Sterling and Draper are visiting a client in Los Angeles. Joan's decision to go after a new account on her own leaves Pete furious and frustrated.

Don is preoccupied with keeping Sylvia's son from being drafted, Peggy has a rat in her apartment, Don and Ted bury the hatchet, Pete has a problem with his mother's new nurse, and Sally makes an accidental discovery about her father.

With his personal and professional life crumbling around him, Don positions himself for a change of scenery. Meanwhile, Pete's life is falling apart as well, thanks to the meddling of Bob Benson.

Don is on the outside looking in on the forced indefinite paid leave from his job. While Ted heads back to New York for a few days, Don takes the opportunity to head to Los Angeles in part to meet with a California transformed Pete while he reunites with Megan, who is living full time there while pursuing what looks to be a promising acting career. Back in New York, Peggy avoids Ted at all cost while she learns to deal with the new "Don", Lou Avery, most specifically on the Accutron account for which she is getting consulting help from Freddie Rumsen. On top of that, she is also having to deal with being a landlady to who she believes are overly demanding tenants. Ken feeling overworked leads to Joan taking over his scheduled business meeting with Wayne Barnes, the new Head of Marketing for Butler Footwear. Barnes' news results in Joan taking what she hopes will be seen as decisive and preemptive action in overcoming a potential problem, action which she hopes demonstrates that she deserves to be more than just a glorified secretary. And Roger meets with Margaret on her request, the two who have been somewhat estranged over the last few months. Their individual new approaches to life may result in a friction-free reunion.

Sally discovers that Don is not working, Pete lands a big account but is undercut by management, and Joan is forced to move some secretaries around after Lou and Peggy have some problems.

After a fight with Megan during a surprise trip to California, Don decides it's time to get back to work. Meanwhile, Betty joins Bobby on a field trip to a farm.

Don returns to work, but quickly falls off the wagon after learning that he's been assigned to Peggy. Meanwhile, Roger and his ex-wife go to a commune to rescue their daughter, who has abandoned her child.

Don and Peggy prepare to pitch to Burger Chef, one day after the Apollo Moon Landing. Meanwhile, a power struggle in the firm between Sterling and Cutler leaves Don's future hanging in the balance.

The partners discover that the firm is losing its independence and there's nothing they can do about it. Peggy is not sure if she wants to come along. Meanwhile, Pete and Trudy have trouble getting their daughter into private school.