Freddy returns with a valuable new client, the firm reluctantly throws a Christmas party for its most important client, and Don prepares for his first Christmas away from his children.

Peter finds out that he will become a father, and has to break some bad business news to his father-in-law. Meanwhile an office focus group study for a client has some unintended personal consequences for Don.

Don has a wild lost weekend after winning a CLIO award, while Peggy is forced to work all weekend in a hotel room with an "uninspired" co-worker. Meanwhile, Peter is livid after he learns that the other partners hired Ken Cosgrove.

Don deliberately delays returning an important call from California, because he knows it's bad news about Anna. Instead, he keeps himself occupied by forcing Peggy to miss her birthday dinner to pull an all-nighter with him for a client.

Sally makes an unwelcome surprise visit to the office to see Don, Peggy tries to stop an acquaintance from publishing an article that could get her in hot water, and Roger Sterling tries to reconnect with Joan.

Don becomes frightened that his lie will be exposed when government agents question Betty about him, Lane has shocking news for his father when he comes to bring him home, and Joan considers having an abortion.

The partners try to keep their cool after they discover that Roger has lost their biggest account, Peter's wife goes into labor, and Don tries to convince Faye to compromise her ethics to drum up new business.

Don makes a bold, desperate move to save Sterling Cooper Draper Pryce, but the other partners are furious with his actions. Meanwhile, Sally's psychiatrist suggests that she is improving, but Betty is skeptical.

Don takes the kids to California and comes back with a surprise announcement. Meanwhile, Betty fires the kids' nanny before they move out of the old house over one questionable incident, and Peggy gets a shot at a new account.

Megan throws Don a surprise birthday party, the war between Pete Campbell and Roger Sterling intensifies, and new mother Joan begins to wonder if she still has a job when she's ready to come back.

Megan is hurt by Don's negative response to the surprise party, Lane finds a missing wallet in a cab, Joan makes an unexpected visit to the office, and Pete makes a play for a bigger office.

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.

Don gets a visit from the in-laws and his children just as he's about to receive a prestigious award and tries to save the Heinz account. Meanwhile, Peggy and her boyfriend take the next step in their relationship.

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.

A depressed Betty tries to make things uncomfortable for Don and Megan, Roger tries to take out some secret weapons for a meeting with a prospective Jewish client, and Don makes a snap judgment that angers the creative department.

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.

Lane's entire world comes crashing down after getting busted for forging Don's signature on a check, and Sally experiences an awkward rite of passage while spending the weekend with the Drapers.

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.

While Don continues his affair with Sylvia, Pete's latest infidelity threatens his marriage. Meanwhile, Peggy's icy relationship with her new staff continues, but she also gets an unlikely tip on a potential new client.

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.

As the firm prepares to go public, Don and Pete's actions cause them to lose two huge clients. However, Roger uses a new connection to put them in position to gain their biggest client ever.

Things quickly become awkward after the two firms merge, Don asserts his dominance over Sylvia, Pete has to deal with his ailing mother, and Bob Benson helps out a sick Joan.

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.

Peggy becomes unsatisfied with her apartment and with Abe, Don has an eventful weekend with Betty while Megan has problems on the set, Roger has time with his grandson, and Pete begins exploring his options outside the firm.

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.

Don renews his battle with Ted after seeing his relationship with Peggy, Sally interviews at a boarding school, and Pete discovers Bob Benson's background.

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.

While Lou becomes the object of ridicule for the copy writers, Don tries to get away to California after a call from his pregnant niece. Meanwhile, the new office computer drives Ginsberg to the brink of insanity.

Peggy has second thoughts about her Burger Chef campaign when Don is asked to pitch her commercial, Pete visits his wife and daughter on his trip back to New York, and Bob Benson gets some surprising news from G.M. about the account.

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.

Don is oddly drawn to a diner waitress as he learns about the loss of an old acquaintance, Peggy and Joan are disrespected by a chauvinistic client, and Cosgrove is in for big changes after his biggest business connection retires.

While Megan comes to New York with her mother and sister to collect her belongings, Don has a romance with the waitress. Meanwhile, Peggy and Stan work with a famous photographer on a commercial shoot.

Don decides to sell his apartment, Joan stumbles into a relationship while on a trip to Los Angeles, Glen tells Betty and Sally that he is going to Vietnam, and a copywriter gets in trouble for his rude behavior to a client.

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.

Don goes AWOL from McCann Erickson in the middle of a meeting. Joan quickly gets fed up with the sexism at the new firm. Roger and Peggy put off reporting to their new jobs as long as possible.

Don is stuck in Oklahoma after his car breaks down. Betty discovers that she is not in good health. Pete gets an unexpected job offer that could enable him to get his life with Trudy and his daughter back.

Don's journey ends in California with Anna's niece, Stephanie, where he contemplates his future. Roger decides to marry Megan's mother, Marie. Joan has a business proposition for Peggy, who is coming to terms with her feelings for Stan.

Megan throws Don a surprise birthday party, the war between Pete Campbell and Roger Sterling intensifies, and new mother Joan begins to wonder if she still has a job when she's ready to come back.

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.

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.

Don takes the kids to California and comes back with a surprise announcement. Meanwhile, Betty fires the kids' nanny before they move out of the old house over one questionable incident, and Peggy gets a shot at a new account.

A depressed Betty tries to make things uncomfortable for Don and Megan, Roger tries to take out some secret weapons for a meeting with a prospective Jewish client, and Don makes a snap judgment that angers the creative department.

The partners try to keep their cool after they discover that Roger has lost their biggest account, Peter's wife goes into labor, and Don tries to convince Faye to compromise her ethics to drum up new business.

While Megan comes to New York with her mother and sister to collect her belongings, Don has a romance with the waitress. Meanwhile, Peggy and Stan work with a famous photographer on a commercial shoot.

Don gets a visit from the in-laws and his children just as he's about to receive a prestigious award and tries to save the Heinz account. Meanwhile, Peggy and her boyfriend take the next step in their relationship.

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.

Megan is hurt by Don's negative response to the surprise party, Lane finds a missing wallet in a cab, Joan makes an unexpected visit to the office, and Pete makes a play for a bigger office.