A review of tonight's "Mad Men" coming up just as soon as I have your wig ready, ma'am...

Early in "The Collaborators," Don explains to Ken that they're going to have to go along with Raymond's demand that they not pursue business with Heinz's ketchup division, because even though it's a bigger account than beans, vinegar and sauces, Raymond was there for SCDP in its hour of need, and "Sometimes, you gotta dance with the one that brung ya."

It's a professional loyalty that Don has sworn by often on "Mad Men," but that kind of loyalty has always proven harder for him to stick to in his personal life. He didn't want to cheat on Betty; he just couldn't stop himself. He thought Megan would make him happy enough to maintain his fidelity; now he's carrying on an affair almost literally right under her nose. Don invokes the Germans at Munich to Pete as a group who were given everything they wanted to be happy and yet still insisted on more, and we know that he understands that mindset all too well.

"The Collaborators" is an hour soaked in infidelity, both literal and figurative. Don continues his affair with Sylvia, and each of them has to deal with spending time with their partner's unsuspecting spouse. Pete (again following Don's path, whether he realizes it or not) also can't resist fooling around with a neighbor, but it turns disastrous when Brenda shows up on his doorstep with a bloody nose, making it impossible for Trudy to feign ignorance anymore. Raymond compares the idea of Don working with Timmy from the ketchup division to "watch(ing) that guy screw my girlfriend." And Peggy, who's already walked out on Don, now begins outright cheating on him by giving Ted a chance to poach Heinz ketchup for himself. (That Don has already decided against SCDP going after the account is beside the point; Peggy knows how Don will react if Ted gets it.)

Because so many of these affairs are happening close to home — Don's had affairs before with women his wife knew, but never one who lived in the same building — they have the potential to blow up at any moment. Jon Hamm's done plenty of great silent acting in the past on this show, but Don's reaction to unexpectedly finding his wife and his mistress having a tearful heart-to-heart in his living room is right up there with the best of them. Ditto Alison Brie in the sequence where Trudy came back from dropping Brenda at the hotel, her body language saying all we needed to know about the hell Trudy would unleash on Pete the next morning.(*)

(*) Insert usual delight that the same actress can give a performance like this and be Annie on "Community." Acting!

But there's more than affairs — or perhaps less — going on in "The Collaborators." We get another flashback to Dick Whitman's childhood relationship with prostitution — here finally explaining previous references he's made (like in his conversation with the madam in "Signal 30") to having been raised in a whorehouse — then return to Don and Sylvia post-coital, as he literally hands her a wad of cash to help with her money troubles. Pete tries to chase Brenda (who came in the first place in search of "Hair" tickets) out of his apartment like he's in a hurry to complete the transaction. And, of course, we welcome back Herb from Jaguar, much to the displeasure of both Joan(**) and Don. Too often in this world, sex is transactional.

(**) On the one hand, that's only two real scenes in the first three hours of the season for Christina Hendricks (three if you count the encounter with Herb and then the drink in Don's office separately). On the other, boy did Hendricks make her time tonight count. I'd like to think that even if Don didn't have to go meet with Herb, he'd have known to clear the hell out of his office to let Joan have her space after having to be around that person. Season 5 was also Joan-light for stretches, but ultimately Hendricks got a lot to do; I assume that'll be the case this year, as well. 

Don undermining of Herb with the Jaguar execs — and then shaking his hand when he wouldn't do it earlier — was a thing of beauty. It doesn't make up for failing to stop Joan a year ago, but it at least gives him the satisfaction of preventing the creep from getting more, more, more from him and the rest of the agency.

The problem is that Don himself is a bottomless pit of want, and after a point it becomes exhausting to him. (He's so tired of the lies and cheating that he just sits on the floor outside his apartment in the episode's closing scene.) When Megan finally tells him about the miscarriage, he suggests he'd be fine with them having kids if that's what she wanted, but he's saying that while he's already checked out of this relationship. (Though he seems genuinely concerned for her well-being on getting the news, it doesn't stop him from going back to Sylvia the very next night.)

When Trudy kicks Pete out of their house, it's with the understanding that they will stay married for the sake of appearances — "I refuse to be a failure," she explains coldly — and that he'll have to appear when called upon by her. It's no longer a marriage, but another business arrangement. And is it any worse a situation, ultimately, than what's happening in Don's apartment building? Megan and Dr. Rosen may be in the dark right now, but this will come out, surely. And who gets bloodied then? Don? Rosen? Megan?

Some other thoughts:

* This was a much more interesting episode than Jon Hamm's directorial debut, "Tea Leaves," and not just because he wasn't stuck introducing Fat Betty this time around. Hamm was fairly candid in talking to Dan Fienberg about how little control he has over the final product of his episodes, but this one looked good, and whoever was responsible for using the "Don't Look Now"/"Out of Sight"-style intercutting between Don and Sylvia at dinner and them having sex afterward (just as Don was promising they would) did an excellent job of conceiving and executing it.

* After getting a screener for the premiere, I'm back to watching live like everybody else for the rest of the season. This means, among other things, that I get to be reminded of just how random and abrupt the act breaks for this show are, particularly the one where Pete tells Brenda to hurry it up so he can get to work. Some basic cable shows take advantage of the commercial breaks to build tension, but that's not how "Mad Men" works; the longer the show's on, the less it seems that the experience of watching it on AMC (as opposed to later on disc, Netflix, etc.) is taken into consideration in the shaping of each hour.

* Several guest stars of note here, including Collette Wolfe (who was Travis' girlfriend Kirsten on "Cougar Town," among other roles) as Brenda, Kip Pardue as Timmy from Heinz ketchup, and (because I forgot to note his presence last week) Trevor Einhorn (aka Frederick Crane from "Frasier") as one of Peggy's terrified copywriters.

* And now we see that Don's second wife also has a tendency to fire the help when she gets upset. Though at least here, we got some inklings last week that Don was unhappy with her work, whereas Carla was an angel to Betty and the kids.

* Another way in which Peggy is copying Don: she also has a black secretary, and is trying to encourage her advancement in the same way she clumsily attempted with Dawn last season.

* We knew that SCDP had to dump Clearasil back in season 4's "The Rejected," and that Ted's agency picked it up. Now we see that Peggy is once again handling an account she did so well with back in her Sterling Cooper days.

* It's mainly a background element, other than Don and Rosen's discussion about the war, but we get to our first major 1968 landmark with the Tet Offensive, putting the events of this episode at the very end of January.

* Another transaction: Bob Benson refuses to take Pete's money for the toilet paper, no doubt because he has designs on screwing Pete over at a later date.

* The episode closes with Bing Crosby's "Just a Gigolo," but if you're of a certain age, you hear those lyrics and immediately flash on the David Lee Roth video.

What did everybody else think?

Alan Sepinwall may be reached at sepinwall@hitfix.com