In retrospect, the bombshell with which "Mad Men" concluded last season was inevitable.
With a busted marriage behind him and a romance in high gear with a self-assured psychologist, Don Draper pulled a fast one in the finale, proposing to his twentysomething secretary just days after they first slept together.
This was classic Don. He was seizing what appeared to be a quick fix — the devotion of a sexy younger woman he said "got" him — after he had spent a season lonely and lost, in a tailspin. He needed the recovery, the structure, the renewed sense of identity she seemed able to provide. And (though only time will tell for sure about this) maybe Don, facing middle age, felt the need to illustrate that durable truism: There's no fool like an old fool.
"He's smiling like a fool, like he's the first man who ever married his secretary," scoffed one of his ad-agency colleagues in the finale, which was set in October 1965 and aired what seems almost that long ago (though it was actually October 2010).
Now — glorioski! — "Mad Men" begins its fifth season on Sunday, March 25, at 9 p.m. EDT on AMC. Viewers who want to keep the re-entry experience pure are duly warned: Below are a few tiny spoilers.
For one thing, Don (series star Jon Hamm) seems still happy with Megan (Jessica Pare). And why not? His bride is an ooh-lah-lah French-Canadian who channels the glamour of Jackie Kennedy by way of Jean Shrimpton. She has Don glowing.
"I don't recognize that man," frets Peggy (Elisabeth Moss) to another agency co-worker. "He's kind. And patient."
"And it galls you."
"No," she says. "It concerns me."
The two-hour premiere, which picks up during a Memorial Day weekend, soon reveals the Drapers' marital dynamics are spicier than Don (or the audience) might have guessed — particularly after Megan surprises him with a party for his 40th birthday at their swanky high-rise apartment.
In the days beforehand, she voices high hopes for the celebration.
"You've never seen me throw a party," she tells Peggy. "Everyone's gonna go home from this, and they're gonna have sex."
Anyone but the love-struck couple might have predicted from the outset: Megan's continued employment at the Manhattan agency Sterling Cooper Draper Pryce (where, naturally, the former secretary landed a promotion) has not been without awkwardness and resentment.
"I don't think those people like me," she says to Don.
"That's not true," he insists.
"Well, I'm not sure I like them," she declares.
Any "Mad Men" devotee could relate to not liking them. While the show's characters remain delicious to watch, with most of them lovable in their authenticity, no one is what you might call warm-and-fuzzy.
Indeed, they seem to be getting on one another's nerves more than ever as the episode plays catch-up after all these months away.
Pete (Vincent Kartheiser) has a new home and a baby with his wife, Trudy, but, as usual, he feels under-valued at the office as he manages the bulk of the accounts.
Joan (Christina Hendricks) is on leave from the agency with her new baby, as she holds on to the secret that the father isn't Greg, her military-surgeon husband now in Vietnam, but instead Roger (John Slattery), the sardonic, gin-soaked agency partner whose glad-handing function at SCDP now seems questionable.
Even hardworking Peggy seems to have lost her creative mojo — at least with one client, Heinz, whose baked beans she proposes showing animated in a commercial, dancing into their can.
"You ever see beans up close?" asks the client as he nixes that idea. "They look like a bunch of bloody organs. And it's not just for fellas like me that saw things in Korea."
Only stiff-upper-lip British partner Lane (Jared Harris) apparently has made peace with lowered expectations for his life. But in the premiere he allows himself a flicker of hope that his life might still take a naughty turn.
The episode is book-ended with glimpses of the civil rights movement, which has spread to a sidewalk in midtown Manhattan. And at Don's birthday party, arguments arise about the wisdom of the nation's involvement in Vietnam.
Clearly, things have kept on changing since the start of the "Mad Men" saga, initially set in 1960. It will continue at least two more seasons, fulfilling series creator Matthew Weiner's original vision of covering that full, tumultuous decade.
But the changes "Mad Men" tracks so vividly aren't national in scope, but the changes its characters undergo. This season's premiere continues the rich "Mad Men" narrative style — a purposeful meandering, an uneasy drift of the characters' lives where time is always threatening to get away from them.
Just consider Don Draper, the charismatic but tormented hero, who now, more than ever, appears to have it all. In the bathroom slathering his Hollywood-handsome face with shaving cream, he peers at himself in the mirror. There's a flash of dread in his eyes, and a not-so-young-man's bags apparent under his eyes.
What is he thinking? Viewers can't be sure. But that's why they keep watching. They can't be sure they aren't thinking the same thing.