'Mad Men' Premiere Recap: All You Need to Know About the Season 7 Opener

— -- "Mad Men" is back, and with it, Don Draper, Roger Sterling (now sporting a very shocking new mustache), Peggy Olson, and the rest of the gang.

Season seven, which premiered Sunday night, takes place in 1970, only made evident by the blaring of President Nixon's address to the nation on the situation in Southeast Asia in the background at one point.

At this point, everybody in the AMC drama seems to be reckoning with how their choices have shaped their lives and what could have been had they made other decisions.

There will be a lot said Monday about how the show dealt with what Ken called "the life not lived" and the difference between dreams and reality. If you haven't seen the show yet, some spoilers lie ahead.

Here's what to know:

Don Draper: At the start of the episode, Don, newly divorced, is casting models to star in a Wilkinson fur ad, directing them in a manner that echoes the harsh way he once commanded Sylvia Rosen in the bedroom. Later, with one of his girlfriends asleep next to him, he dreams that Rachel Menken comes in to audition, wearing very little besides the mink coat she's meant to sell. "I'm supposed to tell you, you missed your flight," she purrs after admiring herself in the mirror. With that, she turns to leave. "Rachel," he calls out. "You're not just smooth. You're Wilkinson smooth." Unable to shake the vision, Don asks his secretary to phone Rachel the next day. As it turns out, Rachel died of leukemia just days before. "She lived the life she wanted to live," her sister later assures Don. "She had everything."

Meanwhile, Don also starts a casual affair with a waitress named Diana, whom he first meets while on a group date with Roger. Roger acts rudely toward her, and, as penance, leaves almost a $100 tip. A few days later, Don returns to the diner and he and the waitress, whom Don is convinced he knows, have sex in the alleyway. He seems curious about her afterward, but during a subsequent visit, Diana tells him that he "got his $100 worth" and should leave her alone. But naturally, Don, now more open about his past and also, his feelings, wants to talk. "I had this dream about a woman that I once knew. And I found out the next day she had just died," he told her. Diana asks if he thinks that she's the dead woman and he says no. "I want you to think very carefully about when you really had that dream because when people die everything gets mixed up," she responds. "Maybe you dreamt about her all the time. ... [When] someone dies you just want to make sense out of it but you can't."

"I'm not saying this to lead you on or make you more interested but the next time you come in here please bring a date," she concludes. "I just work here."

And with that, "Is That All There Is?" begins playing.

Ken Cosgrove: Ken's father-in-law, a big client, is retiring, and Ken, who oversees the account, gives him a nice set of golf clubs to celebrate. His father-in-law is touched. After all these years, he says, he can finally have some fun. This strikes a nerve with Ken's wife, who encourages him to quit his job and follow his true passion: writing. Life is too short to be unhappy, she tells him. The next day, at the urging of McCann, Roger fires Ken and tells him to give his accounts to Pete. Shortly thereafter, Don finds Ken sitting in the hallway looking bewildered. "Do you wanna hear something spooky? My father-in-law retires and my wife says, 'I want you to quit, you're wasting your life. You should write that novel.' And you know what? I think I was gonna do it," he tells Don. "And the very next day they fire me? Can you believe that? ... That's not a coincidence. That's a sign." "Of what?" Don asks. "The life not lived," Ken responds.

Pete Campbell: Pete doesn't figure prominently in the first episode, but he does encourage Ken's ambition to become a novelist, telling him he should write adventure books. As they continue to chat, Pete reflects on his stint working in L.A.: "I thought I was really changing my life when I went out to California," he says wistfully. "Of course now it sort of feels like a dream, but at the time it felt so real."

Joan Holloway and Peggy Olson: Joan and Peggy are working on a campaign for Topaz pantyhose, and they have to sit down with their colleagues at McCann. It doesn't take long for the three men in the meeting to start making suggestive comments about Joan's body. "You should be in the bra business," one says, ogling her. "You're a work of art." In the elevator, Joan is seething, but Peggy tries to get her to look on the bright side -- at least they got what they wanted out of the deal. And besides, Peggy adds, Joan does dress in a way that attracts attention. "So what you're saying is, I don't dress the way you do because I don't look like you," Joan snaps. "And that's very, very true."

That fight sets the tone for both women's storylines in the premiere. Joan immediately goes shopping for a new wardrobe in what appears to be the same department store where she briefly worked in season three. After Joan decides to purchase shoes and expensive dresses, the saleswoman recognizes her and offers her old employee discount. "That's tempting," Joan icily responds, "but I think you have me confused with someone else."

While Joan tries to embrace her new life as a high-powered, rich partner at the ad agency, Peggy embraces her feminine side and agrees to be set up on a date. When the waiter brings her beau veal instead of the lasagna he ordered, she's obviously put off by his relaxed attitude toward it. Why would he eat something he didn't order, she asks. "Johnny said you were the kind of girl who doesn't put up with things," he responds. "He said you were funny and that you were fearless."

After that, they hit it off, and impulsively agree to jet off Paris together. However, Peggy can't find her passport, and because she doesn't want to sleep with him on the first date, she asks him to go home and call her soon.

The next morning, Peggy wakes up hungover and the spell from her magical first date seems to have worn off. At work, when asked about the trip, she brushes it off. "I had too much wine and I totally embarrassed myself," she says. "I'm not going to get on the plane with somebody I barely know."