Back in Season 4, and just off the nadir of Anna's death, and his own bottoming out in a haze of Canadian Club and reckless womanizing, we first heard Don Draper in voice over, he said:
When a man walks into a room, he brings his whole life with him. He has a million reasons for being anywhere, just as him. If you listen, he'll tell you how he got there. How he forgot where he was going, and that he woke up. If you listen, he'll tell you about the time he thought he was an angel or dreamt of being perfect. And then he'll smile with wisdom, content that he realized the world isn't perfect. We're flawed because we want so much more. We're ruined because we get these things, and wish for what we had. 
The Runaways was a lot about flaws, about wanting more, or getting the things we thought we wanted but discovering we wanted something, anything, else. And when that realization hits, our inclination may be to run away, whether that is literally so, as Stephanie did (turning her back on a college education and dropping out from "society"), as Sally threatens to do (unimpressed with the wealth and prestige her parents have separately accumulated and wanting nothing more than evading the overbearing thumb of her mother), or as Megan appears to want (able to pursue her career without living hand-to-mouth but too fearful to leave her husband and trying to make it on her own). It is not coincidental that this episode echoes that mid-Season 4 vibe. Like then, Don is trying to claw his way out of a hole he has dug for himself, except this time, it's not the death of the one person who knew everything about him and still loved him  that he is trying to overcome, but rather, the crumbling of his marriage and his nascent attempts to regain his good name at work.
So it was apt that Stephanie Horton, the niece of Anna Draper we last saw as a sun-kissed college co-ed calls for help as she's devolved into a seven-months pregnant hippie whose "old man" is locked up. Don may have only been, according to Stephanie's mother, "a man, in a room, with a checkbook,"  and maybe he is that to Stefanie too, but Don's inclination is to help. As luck would have it, Stephanie is in the City of Angels and Don offers her Megan's place as a temporary home until he can get there. Megan, planning a party and hanging out with her friend Amy, seems sympathetic, but once Stephanie gets there, their interaction is decidedly chilly. It goes south when Stephanie comments on Megan's engagement ring (which was Anna's) and the whole thing dissolves in backbiting and Megan's writing of a $1000 check to move Stephanie along before Don makes it out to see her. You see, Megan can't countenance the presence of others knowing Don's secrets when that redounds to making her look the fool - someone who has tolerated a mountain of bad behavior (and may be engaging in some of her own - but more about that later), is living this odd fiction of a bi-coastal, but on-life-support marriage, or just the fact that Don has this odd past that she would just as soon not be reminded of.
By the time Don arrives, preparations are in full effect for a late 60s hippie shakedown - complete with banjo-led jam session and Megan engaging in a revealing pas de deux with a fellow long hair that doesn't sit well with Don. When Harry Crane shows up with his latest paramour, he and Don alight to a bar, where Harry shares the news that the firm is in discussion with Phillip Morris to rep their cigarette, "Commander." Of course, Don realizes the consequences of this, he's persona non grata in the tobacco world because of "the letter" he wrote after American Tobacco left SCDP,  and realizes this is a management ploy to force him out. When Don returns to Megan's "pad," she graciously offers up her friend Amy for a threesome. Don protests, but not too much. The next morning, Stephanie's call sends Megan off again and Don heading for the exit.
Upon his return to New York, and with the confidence of that Don Draper, Don strolls into a private room in the Algonquin and reminds the Phillip Morris executives just what they would be losing if they forced SC&P's hand and got Don to quit in exchange for their business. The not-so subtle jab did not sit well with Lou Avery or Jim Cutler, but swaggering Don chews up guys like Lou and Jim for lunch and washes them down with an Old Fashioned. Jim Cutler may have angrily shut the door to his cab in Don's face, but the effect was akin to that of a fly being swatted away by an elephant - Don barely registered a response other than his well-known dismissive, and unspoken "fuck you."
Indeed, this snippet echoed even further back in the show's history, to another California jag Don went on during yet another tumultuous time - Betty's kicking him out of the house in the wake of his affair with Bobbi Barrett.  Back then, after escaping to California and renewing his energy at Anna's home,  Pete Campbell let Don know about the pending merger Duck organized between Sterling Cooper and PPL.  This information allowed Don to deftly knee cap Duck by letting the PPL team know he (Don) did not have a contract and was planning on leaving the agency if Duck led it.  Unspoken in his threat was how much weaker the firm would be without his singular talent. Now, faced with a conspiracy to minimize him, Don pulls a similar stunt, reminding the Phillip Morris executives that he and Lou have the same amount of experience working with tobacco, but Don has the added benefit of knowing the other side's strategy (and oh yeah, he's Don Draper and the other guy is Lou Avery). In both instances, Pete and Harry were not enamored with the devil they knew, but the devil they did not know looked even worse, allowing Don to avoid whatever fate would have otherwise befallen him.
The Runaways had an incomplete feel that also closed loose ends. Ginsberg, who blew onto the show with so much promise, dissolved in a weird, conspiratorial puddle, his sliced nipple (?!) the result of perhaps some undiagnosed mental condition or just the whirring of that IBM computer (I'm guessing the former). Betty tuned up her petulance to 11, first, scrapping with Sally after Sally broke her nose horsing around with her friends and then, speaking in an impolitic manner during a dinner party she and Henry threw. Betty's feelings of frustration are understandable - she questions whether her children love her, and she is watching as other women go into the work force, earn their own money and put the home maker lifestyle behind them, while she just burns through cigarettes, nursing whatever petty grudges she has. She wishes she could run away from a life that once upon a time was fully formed and accepted, but, in the exponential societal shifts occurring in America in the 1960s, is quickly becoming passé.
And what of Megan? The obituary for her marriage to Don has been written for some time, just waiting to be published. Because we are not privy to what goes on off screen, we do not know if Don has again asked for another chance (likely) or if Megan simply likes the "bread" (to use Stephanie's term) Don provides, which allows her to cut $1000 checks without a thought.  But Megan's facilitation of a three way with her friend Amy may have just been an inelegant way of disguising some other affair she's having. Her flirtation with another party guest harkened back to her Zou Bissou Bissou days,  but this time, Don was not her intended target. And maybe she just wanted to underscore Don's amorality by watching him with another woman (even though, in fairness, he didn't seem overly enticed by the idea), or run away from their marriage in a haze of drugs, or wash away her own guilt at whatever she is doing in Los Angeles without his knowledge, or wearing the ring of a woman who meant more to him than she (or anyone else?) ever will, but appealing to Don's darker side rarely turns out well for others (or him).
As we head into the home stretch of the first "half" of Season Seven, it appears corporate lines are being drawn - basically, the partners, save Roger, are on one side, aligned to torpedo Don in one way or the other , with Roger, and now Harry quietly drifting to Don's side. Out of loyalty? Perhaps. Out of an interest in securing their own place within the hierarchy? Definitely. The wild card, as always in Peggy. It was promising that Don and Peggy had what passed for a civil conversation in the elevator. When Don needs Peggy most, he can sometimes step in it,  but can always appeal to her interest in doing good and creative work. In the meantime, it is still thrilling to watch Don work his creative magic even as his personal life is a complete and utter mess.
PS - Godspeed, Martian.
1. The Summer Man, Season 4, Episode 8.
2. The Good News, Season 4, Episode 3.
4. Blowing Smoke, Season 4, Episode 12.
5. A Night to Remember, Season 2, Episode 8.
6. The Mountain King, Season 2, Episode 12. Though in fairness, Don probably recaptured some of his mojo in Palm Springs as well. The Jet Set, Season 2, Episode 11.
7. Meditations in an Emergency, Season 2, Episode 13.
9. $1000 in 1969 is equivalent to $6,564 in 2014. http://www.dollartimes.com/inflation/inflation.php?amount=1000&year=1969
10. A Little Kiss Part I, Season 5, Episode 1.
11. How Don's impromptu "pop in" to the Phillip Morris meeting didn't violate the "terms" of his return to the agency is beyond me.
12. Shut the Door, Have a Seat, Season 3, Episode 13. When Don advised Peggy he's leaving Sterling Cooper to open a new agency, he simply assumes she will come with him. It is not until he goes to her apartment and makes a more heartfelt plea, that she agrees to leave with him.