Tonight's ironically titled episode of Mad Men, "Collaborators" — which was directed by series star Jon Hamm — offers no shortage of ways in which our main characters betray one another. In last week's premiere, we learned that Don Draper had returned to his philandering ways — but tonight's episode showed that Mad Men's other main characters, including Pete Campbell and Peggy Olson, are just as susceptible to temptation of one kind or another.

This episode wasn't exactly subtle about its thematic concerns, but just in case viewers missed the blinking sign saying "this episode is about prostitution," we were granted an unfortunate reintroduction to Herb, the sleazy Jaguar rep who made sleeping with Joan Holloway one of the conditions of his business. Joan's dressing-down of Herb after he waddles into her office feels like a bit of fan service — she actually delivers the line "I know there's a part of you that you haven't seen in years" as the portly jerk tries to pick her up again — but it's a welcome bit of fan service, finally allowing her to strike back at the man who put her in such an uncomfortable position last season.

But most of "Collaborators" was focused on affairs that were less cut-and-dry (albeit closer than our lead characters would want to admit). In the latest terrible decision of his Charlie Brown-esque life, Pete Campbell's attempt to have a simple, no-strings-attached affair with his neighbor's wife Brenda blew up in his face in less than 24 hours. After clumsily seducing Brenda with the promise of tickets to Hair — which opened on Broadway on April 29, 1968, for anyone looking for additional clarity on where we are in Mad Men's timeline — Pete dismisses Brenda from his Manhattan apartment with characteristic selfishness: "I really have to get back. Can you move it along a little?"

Brenda thought her tryst with Pete was the beginning of something, and Pete thought it was over as soon as he asked her to leave. When Brenda shows up later at Pete and Trudy's house, confiding that her husband has beaten her, it's not exactly difficult for Trudy to put the pieces together — though she also reveals that she's known about his affairs all along shortly before she kicks him out for good. An affair is never something to admire, but this latest mind-bogglingly shortsighted attempt at an affair, which had so many obvious potential consequences, seems like the kind of thing only Pete Campbell would be dumb and self-centered enough to do.

Except, of course, that our "hero" is also having an ill-advised affair with the wife of a neighbor and friend. Don's affair with Sylvia — which played as the "twist" at the end of last week's season premiere — takes up much of "Collaborators," and the inherent riskiness of the affair is a gamble that seems unlikely to pay long-term dividends. Don, unlike Pete, refuses to permit any blurring of the lines in his relationship with Sylvia. "I want you. I want you all the time," he says during their unexpected tete-a-tete at dinner. "But if you suddenly decided you want something more… Well, that's news, isn't it?" Sylvia later agrees to be less jealous, as if that's the kind of thing a person can control. But once again, Don seems to be in pretty far over his head. When Megan reveals to Sylvia that she recently had a miscarriage, it's enough to give Sylvia pause, but it's not enough to make her stop — and when Megan finally tells Don, he has the same reaction.

We've seen Don embark on risky affairs before, and end them relatively unscathed — his dalliance with his daughter Sally's teacher, Suzanne Farrell, jumps to mind — but given his continued friendship with Dr. Rosen, it's hard to imagine any way things with Sylvia can end without some kind of fallout. (Sylvia's insistence that she would never get an abortion is a particularly uneasy moment of possible foreshadowing; if Don knew how strongly she felt, I suspect he'd call off their affair altogether.)

We've also seen Don with prostitutes before, and though he knows Sylvia needs it, his decision to hand her money immediately after sex is an uncomfortable and telling one. "Collaborators" implies that Don picked up his affinity for prostitutes in the brothel where he spent the latter half of his youth, but his connection to prostitution goes all the way back to his birth as the son of a prostitute. His stepmother, Abigail Whitman, derisively called Don a "whore child," but "Collaborators" complicates things even further by showing us the young Don watching through a keyhole as Abigail has sex with Uncle Mack, his surrogate father figure and apparent brothel owner. There's no excuse for treating women the way Don Draper treats women, but with every new, disturbing thing we learn about his past, it's clear that his sexual hang-ups come from a deep-seated place. (Freud would absolutely have killed to have Don Draper on his couch.)

But sexual infidelity isn't the only type of betrayal in "Collaborators." One of the sole heartwarming moments of last week's grim premiere was the revelation that Peggy and Stan had remained friends, calling one another and trading jokes and stories while working late at night — so of course, "Collaborators" found a way to make that depressing, too. When Peggy tells her new boss, Ted Chaough, that Sterling Cooper Draper Pryce had recently had an exploratory meeting with Heinz ketchup (a fact that Stan had casually confided in Peggy), he insists that she try to snag the account. "He's not your friend. He's the enemy," Ted says of Stan when Peggy protests. "Maybe you need a friend more than you need a job."

Peggy seems likely to follow Ted's orders and sell out her friend for a shot at what Ken Cosgrove calls "the Coca-Cola of condiments" — but in a series in which a genuine personal connection is so hard time come by, it seems like a fairly low reward for a very high price. Peggy is clearly modeling herself after Don Draper, but even Don — whose professional loyalty is a lot more reliable than his loyalty to his romantic partners — might not be this cutthroat; he was the only one who objected to dumping Mohawk Airlines to chase American Airlines in season two, and he's reluctant to dump Heinz's baked beans division for a shot at the ketchup business.

"And so we just keep saying yes, no matter what? Because we didn't say no to begin with?" complains Don about Herb's latest absurd demand regarding the Jaguar account. He may be talking about the advertising business, but Don's professional philosophy continues to bleed into his personal life — and his inability to say no to his urges comes at steep cost for everyone around him.

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