Sunday night's episode of Mad Men was a culmination of themes that have been percolating all season. In it, our three strongest female characters (Peggy, Megan, and Joan) make moves to further cast off the shackles of traditional womanhood, with varying successes. The advertising backdrop is the agency's work to win their first car client, Jaguar. That pitch aligns nearly exactly with the message of the overall episode, making this, if not the best (though I think it was), the most thematically cohesive show all season. After all, it's called "The Other Woman."

We start out in the agency, where the team is throwing around taglines—"Jaguar, the mistress who will do things your wife won't"—to make up for the car's inherent issues: It's beautiful but not dependable, or, as Don tells Megan later at the apartment, you need another car to actually take you places. Megan, who's practicing her lines for an audition and clearly doesn't want to have this conversation, asks, "A wife is like a Buick in a garage? Doesn't being a mistress make a car immoral?" before she gets up to leave. So Matthew Weiner gets right to the point here: This episode is about women, and the traditional, expected roles of wife and mom or careerwoman versus the role of mistress, say, but more than that, it's about the comminglings of all of those roles. Not everything is black and white, we learn. 

The Joan-focused plot (and this is really a Joan-and-Peggy-focused episode, with hints of Megan) is quickly introduced as well. We find out that Herb Rennet, head of the Dealers Association and a member of the Jaguar selection committee, is interested in a liaison with Joan who's "built like a B52," as he charmingly puts it. "I sure would like to get to know her better," he tells Ken and Pete, implying their chances of winning the business will be improved if they can make it happen. Pete being Pete, he immediately goes to Joan to ask how she "feels" about such an arrangement, putting it quite bluntly: "We're going to lose Jaguar unless an arrangement is made, and it involves you and Herb."

Pete, for whom any sacrifice that promotes his personal success is worth it, thinks this could be worth the sacrifice, and takes it as a positive sign that Joan responds that the company can't afford what he's asking, calling a meeting with Bert, Don, Roger, Lane, and himself to determine what, exactly, the agency can afford (the going rate for selling your employee, if she is Joan, to a client, if he is Jaguar, is apparently $50,000). Don is the only one who dissents, saying that the work will be good enough to win on its own and walking out. Roger says that he won't stand in the way but won't pay for it either, making this, as Julia Turner writes in Slate, "nothing but his first refusal to pay for something all season." True. Lane is more devious, using this as an opportunity to cover his thieving tracks further (remember when he "borrowed" that money from the agency last episode); under the guise of concern, he convinces Joan to demand a 5 percent partnership stake in the company instead of cash. (This particularly slimy conversation is interspersed with Pete reading to his child from Good Night Moon.)

At this point, we realize that Joan is serious, though the question of why she's willing to do it is one we can debate: Maybe she's sick of being thought of as what, later, Freddy Rumson tells Peggy to stop acting like: "A secretary who's dying to help out." Maybe she wants to do things on her terms. Maybe it's about supporting her family. Maybe she's seen the men she works with behave in so many questionable ways that she thinks it's finally her turn, and at least there's a payoff here. Maybe it's a shot at Roger, or maybe it's a shot at all men. If Joan has been admired for her looks her whole life, as her mother taught her to be, maybe she can finally get something tangible from it. 

Meanwhile, the Peggy plot-line. Peggy has been told she can't work on a car brand, Peggy's been overshadowed by newbie ad guy (of course, a guy!) Ginsberg, Peggy is frustrated. Frustrated enough to, in this episode, tell Ken Cosgrove, with whom, ages ago, she formed a pact—remember that? "You go, I go"?—that that pact is stupid when he brings it up to remind her that he has her back. Peggy is over it. 

Peggy is also a genius in this episode, as sure-footed as we've seen her all season, turning issues with the Chevalier Blanc client into advertising gold. But when she tells of her win to Don, he responds that Ginsberg will take over with that client when Jaguar is done. Peggy, who earlier was put "in charge" by Don says, "I guess I'm not in charge of everything," and as a reward gets money thrown in her face by her boss. This is the beginning of the last straw: The end of it is effectively dissolving the pact with Ken. 

Megan comes into the agency with her red-headed actress frenemy, Julia, who, in a scene that's shades of Antonioni's Blow-Up, "entertains" the copy guys by acting out the part of a jaguar on the table in front of them. Megan, who tells the guys that Jaguar is their problem, not hers, then pays a visit to Don in his office so that she goes into her audition "with confidence," causing Ginsberg to utter, "She just comes and goes as she pleases, huh?" This is a statement you could apply to Peggy and Joan, too; it's a bit like Pete Campbell complaining about women, "Why do they always get to decide?" and it's true and at the same time, it's not. Women are pushing for more control, more decision-making power, more of the ability to come and go as they please, the way the men—at least men like Don Draper—have been doing all their lives. But it's complicated, as later we see: If Megan gets the role she wants, for instance, she'll be in Boston for three months. Don is not happy with that, and says so. But it's not his choice, in the end. Yet it's not really her choice, either. In the audition, the men really only want to look her up and down; Megan's grasp for control in that situation is thwarted, though she's managing to hold on to it with Don. Later, she tells him that if she is forced to choose between him and acting, she'll choose him, but she'll hate him for it. All the norms our characters have known are in flux. 

Pete ham-handedly sets up the arrangement between Herb and Joan, and Ginsberg comes through with the perfect Jaguar campaign, with Jaguar not as mistress but an unattainable woman (who, presumably, has come and gone as she pleased) who is finally attained: "At last, something beautiful you can truly own." Peggy has dinner with Freddy Rumson, who gives her career advice—stop acting like "some secretary from Brooklyn who's dying to help out," for one—and that she should leave. If Don wasn't her boss, he says, he'd tell her the same. 

Don, the flawed man who may be the only good man in this show, save Ken Cosgrove, tries to intervene with the inevitable Joan and Herb rendezvous. He shows up at her apartment and tells her it's not worth it. She doesn't say it to him, but we know it's too late, the decision has been made, and Joan is going through with it, despite her obvious disgust. The scenes with Herb and Joan—he gives her an emerald necklace, compliments her, then gets to the point and she starts to undress, her face frozen—are spliced in with Don giving the pitch to Jaguar, and the lines he gives in that authoritative Don Draper voice that makes you believe anything he says are equally suitable to both situations: Both, in essence, are business. 

Herb, who is all politeness if morally reprehensible, says, "Thank you for the wonderful time. You're a hell of a gal," and Joan leaves, later remembering how Don tried to intervene. When he sees her the next morning, things are changed between them, parameters slightly shifted; when the meeting is called for the partners to come to Roger's office and hear if they've won the business, she is there, too, and he realizes what happened. They win. But Don has lost—and lost further, because Peggy then gives her notice, has gotten another job, a better job paying more money at a rival firm. Despite his manipulations—first he's impressed, then he tries to win her back, then he's bitter and jealous, then he tells her just to leave—she won't change her mind. He kisses her on the hand, a slow, gentlemanly kiss, and she walks out of the office, gets her things, and walks to the elevator, all seriousness, and pushes the button.

The Kinks' "You Really Got Me" starts to play, and suddenly there's a little half-smile on Peggy's face, revealing the inner joy of leaving a job where you've been taken for granted, the excitement of starting anew burbling up. And all of a sudden you realize (as she realizes it, too) that she comes and goes as she pleases, now.

But where are we, without Peggy?