The 'Why' moments on 'Mad Men' for Joan ... and Don

It was a hugely affecting episode and a significant one in the series, which is saying something. It raised questions about character behavior – foremost by Joan, who makes a decision to prostitute herself that understandably shocked – but not limited to her.

I bought Joan's decision, if only because depression – and Joan has been unmistakably depressed – not to mention anger, make you do things you'd never expect.

Is depression and self-loathing the motivation, then, behind the other questionable behavior that I've seen less discussed online: Don's attitude toward Peggy?   More than once in "Mad Men" history, we've seen Peggy rebel at being taken for granted by a curt, dismissive Don, who then comes to his senses. To name two examples, you had "Shut the Door, Have a Seat," in which Don just assumed that Peggy would want to move with Don to the new firm, and you had season four's "The Suitcase," the ultimate exploration of the relationship between the two in all its lows and highs.

Why did "The Other Woman" once again hit the same beat of Don being so cruel and thankless and unmistakably clueless toward Peggy, a beat that directly led to Peggy's dramatic departure.  Why have their experiences not led to a closer connection with fewer misunderstandings?

The handholding scene at the end of the episode was clearly a callback to two other handholding scenes in the series – the one from the pilot ("Smoke Gets in Your Eyes") and the one from "The Suitcase," the product of which seemingly was the deepest of bonds? But the cycle repeated Sunday, only with consequences for having had to repeat. Is the point that you never get away from the clash, that Don is addicted to needing someone he can shit on? Is it, in a way, another reflection on the realities of marriage, with Don's work wife substituting for his real-life ones?

Peggy, like Betty Draper, had finally had enough.  That doesn't mean she might not have wistful regrets down the road, but Peggy had to take a stand. And given her inner strength, she might well succeed in being fulfilled by the next chapter of her life in a way that Betty hasn't. Peggy's confident smile at the end of the episode hinted at as much.

The Peggy situation stands in stark contrast to Joan, who took on the role of Don's work wife a week earlier in "Christmas Waltz," a woman whom Don esteems unreservedly and looks to protect. Don's loyalty to Joan is not lip-service – it's complete. Perhaps, then, Joan is only Don's work mistress, the unreal fantasy that excites but doesn't hurt. But with Peggy, reality intrudes with a blind spot that is recurring, one too many times for Don's sake.

Peggy was too close to Don, further inside his comfort zone than Joan. It's worth wondering now whether Don and Joan, who have been so wonderful together, will ever be the same going forward, what with Joan's heartbreaking actions in the name of the Jaguar account and her own uncertain future.

As for the Emmys ... the episode is a showcase for Hendricks and should be the centerpiece for her chances to earn a third consecutive drama supporting actress nomination. Yet the episode could also bring the one that redeems the Emmy hopes of Moss, who has largely been marginalized for the sake of story on "Mad Men" this year. Moss is once again competing in lead actress, yet she hasn't had much material in 2012 to justify that position. Until Sunday, when she once again asserted why she is one of the best there is.