A review of tonight's "Mad Men" coming up just as soon as I find a hooker who'll take traveler's checks...

"I've never seen anything like this before." -Duck
"I have." -Pete

In the early days of "Mad Men," there was mystery: Who is Dick Whitman? Why is Peggy gaining all this weight? What happened to Peggy and Pete's baby? The show had far more to offer back then besides hints and puzzles, but those early secrets provided an added layer of tension and narrative propulsion, and one more thing to analyze and debate in the week between episodes.

I imagine it must have been very tempting for Matt Weiner to approach each new season after the first two with the intention of piling on a new mystery. We love to ask questions, so why not give us some more possibilities: Why is Joan suddenly wearing an eyepatch? Why is Roger speaking French all the time? How did Peggy become one of the Oceanic Six?

Instead, Weiner recognized that after a while, those sorts of mysteries eventually lose their power, and can retroactively make the earlier mysteries seem like a parlor trick. With characters this deep, and a world and time period this rich, "Mad Men" didn't need big mysteries after a while. Each season could still build to something — the end of Don and Betty's marriage and the heist of Sterling Cooper, Don and Megan's engagement, Lane's suicide and Peggy's departure from SCDP — without requiring clues and guessing games all season long. (Though in the case of Lane's death, there were still hints aplenty.)

Season 6, though, has been rife with history repeating itself, and so it feels appropriate not only that we should be given another year-long riddle — What is the deal with Bob Benson? — but that the solution should be yet another echo of the series' past. Bob Benson is not a sociopath. He's not the bastard son of Dick Whitman and Aimee the prostitute, nor Peggy and Pete's son, unstuck in time. He's not a spy working for the Soviets, for a rival agency, or for a vengeful Guy Mackendrick. But nor is he exactly who he's claimed to be.

Bob Benson is Dick Whitman 2.0. He has a name that deliberately echoes Don Draper's, also grew up in poverty that shamed him — to the point where his former colleagues joked about his parents being siblings — and decided that the only way to escape his shabby origins would be to steal a new life. His crime is lower-scale than Don's — rather than stealing a dead man's identity, he simply stole a pencil sharpener and a Christmas card list, then lied on his resume — but he's another version of the man Pete was so desperate to be rid of eight years earlier.

It's a solution many had speculated about (in broad strokes, if not these specifics), but it's one that also feels right to this show, this universe and some of the themes of this season. And though the cliche tells us that history repeats itself for those who refuse to learn from it, what's so interesting about "The Quality of Mercy" — a superb penultimate hour for season 6 — is that at least one character seems to have studied the mistakes of the past, even if other characters keep making the same mistakes, while some are just desperate to get away before the pattern starts all over again.

The man who has learned from his own history: Pete Campbell, who once again discovers that his chief rival is a slick, handsome shapeshifter — and who recognizes this time that he can't beat him.

It's been almost a decade since Pete tattled on Don to Bert Cooper, and though he's failed to evolve in some ways — check out how publicly nasty he is with both his mother and her nurse, and the fact that he still hangs onto that damn rifle he traded the chip-and-dip for — he's grown wiser in others. He'd likely have an easier time getting rid of Bob (junior accounts man who just happens to be in the right place at the right time) than he did Don (creative star and newly-minted junior partner of Sterling Cooper), but he recognizes there's no point to it. Bob could still outmaneuver him, and besides, he might be more valuable this way. As Cooper told Don the last time this happened, "One never knows how loyalty is born." The Pete who emerges from his failed attempt to get the partners to reassign Bob is a bitter, paranoid wreck; the Pete who leaves Bob's office after granting him a reprieve is once again king of the castle. It may seem like a surrender to us, but a shaken Bob Benson feels like he's just been given his life back, and that puts Pete back into a power position.

One floor below Pete, Don is just as successful at putting a professional irritant in his place, as he emotionally destroys Ted by making his shameless flirtation with Peggy into the blinking neon subtext of a meeting with the St. Joseph aspirin executive. Byron has no idea what Don is talking about, but everyone else in the room does, because it's been unmistakable to anyone who's had to be around Ted and Peggy the last few weeks.(*) You could look at this as Don also learning from history: he was just as distracted and goofy and reckless in the early days of his marriage to Megan (or how much he wasn't thinking with his head with Sylvia), and perhaps now he can recognize it when he sees the behavior performed by two other people. But that seems less a motivating factor than his jealousy — emotional, not romantic — of Ted being so close to Peggy. Earlier on his Megan-mandated day off, Don shoots down Harry's attempt to revive the Sunkist account; as soon as he gets home from running into Ted and Peggy at a screening of "Rosemary's Baby," he's making calls to the California, and preparing the first of several major anti-Ted offensives.

(*) The show's traditional approach to the calendar, in which each episode in a season takes place about a month after the previous one (this one's late October, after Jackie Kennedy married Aristotle Onassis, but before the election), sometimes means emotional developments happen off-camera. The last Peggy/Ted-heavy episode, "The Better Half," ended with him attempting to put a professional distance between the two of them. Last week's episode suggested that he still had feelings he couldn't entirely hide, but that's still a fair distance from the two of them carrying on like an actual couple. It's not that I don't believe they could have gone from Point A to Point B in the weeks since Peggy killed a rat in her apartment, but that it would have been interesting to see them gradually slip into this mode. 

But as brutally effective as Don is at crushing Ted's spirit, he ultimately finishes the episode no happier than he began it. Our first glimpse of Don in this hour is an overhead shot of him lying in the fetal position on Sally's bed, still drowning himself in booze after what his daughter witnessed in last week's episode. Our last is a similar shot of him in the same position on his office couch, moments after Peggy — perhaps the only woman he knows whose disapproval can cut him as deeply as Sally's — has called him "a monster." When Peggy barges in to confront Don about the maneuver he pulled, he's lying comfortably on his back; after she's done, he goes fetal again. (In between those two scenes, he briefly — and hilariously — is called on to imitate a crying baby.) He emotionally destroys Ted and for once is in full command of a meeting. But the clarity he gets from the day off does little to solve the underlying problem: Don Draper is a profoundly selfish individual who does whatever is necessary to get what he wants, and in the process consistently pushes away the people he cares most deeply about.  

What Sally witnessed last week wasn't as physically painful as what Ken endured when the good ol' boys from Chevy accidentally shot him in the face while hunting, but both events have left scars, and set them running. Ken successfully extracts himself from a life of traveling to Detroit, while Sally decides the only way to deal with two parents that she hates is to attend boarding school — specifically, Miss Porter's (still in existence today), famously attended by Jackie Onassis when she was just Jackie Bouvier.

But the thing is, running away from your problems is a move she inherited from her father, and there's a sense that hanging around with the mean girls like her two hosts could only push Sally closer to being like her mother. Betty even offers Sally a cigarette on the ride home from Connecticut, and when she notes that Don must have given her beer at some point, Sally says — in a tone so Betty-esque that it disturbs even Betty herself — "My father has never given me anything." Sally's still hanging around Glen Bishop — now strong enough to climb into a second-story window and beat up his turtleneck-and-sandal-wearing buddy Rolo — who's a link for her to more innocent times in Ossining, even though here he's supplying booze, pot and, eventually, a clumsy fight with Rolo. Sally smiles at the sight of it, happy to have at least one older man in her life who will stand up for her.

What I loved about "The Quality of Mercy" was the way that it derived tension from mystery and from more straightforward storytelling. Pete's discovery of Bob's secret origin, and their confrontation in Bob's office, crackled. But so did Don's smackdown of Ted and Peggy in the St. Joseph meeting — a scene so tense I'm not sure I was breathing for certain portions of it. The latter scene had its own small mystery — What in the world is Don going to say to the client here? — but the point of his maneuver, and the immediate, devastating impact of it, was clear from the outset.

It's great when Weiner (and his staff, with veterans Andre and Maria Jacquemetton contributing this script) can string us along for months on end with questions about what's really going on, whether characters have hidden identities or motives. But that can also lead us down distracting rabbit holes, like some of the stranger Bob Benson theories, or that period a couple of weeks ago when half the Internet was convinced that Megan had turned into Bruce Willis at the end of "The Sixth Sense." "Mad Men" can do mystery, but some of its best, most powerful moments have nothing to do with secrets and everything to do with how well we know and understand this fascinating, dysfunctional collection of individuals.


Some other thoughts:

* Just when I thought Don Draper as a crying baby couldn't possibly be topped for unexpected "Mad Men" belly laughs, we got Joan Harris as a Jewish neighbor suggesting a bowl of chicken soup. Hands up, everyone who would like to see Christina Hendricks find a new venue in which to play this character on her "Mad Men" downtime. It can be a web series, a new Johnnie Walker ad campaign, part of a sitcom, a one-woman show where Hendricks acts out classic "The Goldbergs" scripts. I don't really care about the specifics. Just make it happen, showbiz!

* I didn't notice if we saw the new SC&P logo in last week's episode, but it was prominent several times here, both in the scene in the lobby where Ted and Don discuss the call to the casting session, and later when Pete walks in on Bob listening to another motivational record and drinking from a new SC&P mug. The rounder typeface in the logo is a far cry from the original Sterling Cooper logo from the early '60s, and seems more youthful even than the SCDP logo.  In a fake SC&P press release that AMC sent out after the episode aired, Jim Cutler is quoted as saying, "The logo for the combined entity is clean, visually-striking, and you have to agree the ampersand is funky."

* Last week, we saw Stan with a poster of eyepatch-clad Israeli military hero Moshe Dayan above his bed; this week, Ken winds up with an eyepatch. Does this mean someone else is eventually going to turn into a series of black dots to match that painting Roger kept in his old office?

* That nightmarish anti-crime Nixon ad Don was watching was part of an entire series the campaign put out in '68 with the "This time, vote like your whole world depended on it" tagline. Some were equally alarmist about the war, hippies, and the state of things under a Democratic administration, but at least one tried to be hopeful about America's youth and Tricky Dick's feelings about them.

* In addition to the Nixon ad and "Rosemary's Baby," also viewed this week: an episode of the revived "Dragnet" (you can hear Harry Morgan's voice as Don ignores Megan's invite to the bedroom) and a Three Stooges film.

* The closing song is The Monkees' "Porpoise Song," aka the theme from their 1968 psychedelic film (co-written by a young Jack Nicholson!) "Head." The Monkees, of course, began life as a commodity — "the Pre-Fab Four," assembled in response to an ad for a TV pilot that needed a band — before the members asserted their own independence and moved into stranger territory like that movie.

* Taking a page from Glen and Rolo, I will now be sure to remark on seeing anyone's home for the first time by saying, "Nice digs."

What did everybody else think?

Alan Sepinwall may be reached at sepinwall@hitfix.com