The advance copy of the new episode of “Mad Men” — the first in too many moons — arrived the other day. It was handsomely packaged, of course, and closely trailed by an e-mail plea from its meticulously controlling creator, Matthew Weiner, who asked critics not to tell you anything that happens when the show returns for a fifth season, two-hour premiere Sunday night on AMC.

What year is the show in now? 1966? Please don’t tell.

What’s up with Don and the secretary he proposed to, Megan? No, don’t say.

Did Joan have Roger’s baby? Hush.

What’s going to happen to Sterling Cooper Draper Pryce without the Lucky Strike account? Shut up about that.

“I know you are aware how strongly I feel that the viewers are entitled to have the same experience you’ve just had,” wrote Weiner, who has four consecutive Best Drama Emmys now (one too many, in my opinion) and has raised cultural alertness for “Mad Men” once again to an all-time high: Check out the retro-designed issue of the latest Newsweek. Pass the windows of any Banana Republic, still pushing its “Mad Men” clothing line and retrofied style dream. Ignoring “Mad Men’s” throwback zeitgeist is, as ever, difficult work. The attention to detail, for which the show is deservedly praised, has apparently extended into how journalists may write about it. It’s as if all of elite television watching hangs in the balance — and perhaps it does.

I’m not here to spoil “Mad Men” but I am, like many, beating around for something new to say about it. The show exasperates me, even bores me sometimes, and yet it is always difficult to look away. It’s my least favorite TV series that I never miss an episode of. If that makes sense.

This new season starts off strong. The contrast is sharper now — the psychological gloom within Sterling Cooper Draper Pryce clashes with the verging sense of psychedelia just beyond Madison Avenue. “What is wrong with you people?” asks Megan Draper (née Calvet, Don’s new wife) during a tiff with her nominal new boss, Peggy Olson (Elisabeth Moss). “You’re all so cynical. You don’t smile, you smirk.

As Megan, the French-Canadian “sexpot” (as more than one man at Sterling Cooper refers to her) Jessica Paré has been a strong addition to the cast, and its new visual inspiration. In just a few scenes, she becomes “Mad Men’s” most watchable new asset.

The 17-month break since “Mad Men” last aired has done us all a world of good. The fatigue has been aired out, the victory laps well finished. What we’re looking at now, to borrow a technological boast from the era, is “Mad Men — in living color,” starting with Megan’s movement and la mode. The first two hours sometimes reminded me of when reruns of “My Three Sons” and “Bewitched” traverse from black-and-white into the whole chromatic array. Something is perceptibly different in shades of tangerine and pink and green.

And evidence of irretrievable change blooms all around Don Draper and company in late spring of . . . oh, what the heck. Everyone who watches the show knows “Mad Men” has worked its way up through the fall of 1965 in season 4. And what comes after that? Yes, 1966. Now you know. (Betwixt “Rubber Soul” and “Revolver,” for those of you who measure the decade that way.) A subtle vibe has turned, and there’s no going back, not since last season when Peggy passed through a pot-clouded party in the New York underground art scene.

Now the black people are protesting outside, as if threatening to become actual characters. I see go-go boots and shorter skirts and blocks of trippy color. I see the first hint of plumage on the men. Don and Megan’s new high-rise apartment is a splash of white carpet and zebra-striped pillows. It’s like their world is about to burst, as we’ve always known it must. This updated “Mad Men” is a mind-blowing retrogasm.

Most of all I see Don getting old. That’s partly because I’m a very simple “Mad Men” watcher who has always rooted against Don. He’s an unlikable man in a show about unlikable people who are all about to get, in one way or another, an astonishing wake-up call. Even the clients who come to the struggling ad firm are newly desperate for edge, looking to jettison the stodgy.

Of all the theories and deconstructions and interpretations proffered about the show— entire books and dissertations on the subtexts, the meanings, the psychology — I’ve never seen “Mad Men” as anything more than the story of a man who’s on the wrong end of a revolution. The misogyny, racism, deceit and entitlement are merely obstacles on the way to the ultimate payoff of a profound cultural shift. I take the theme sequence literally: a man plummeting. I keep hoping the series will end with a metaphorical splat.

But I also see Don getting old because it’s more directly addressed this season. And sorry Matthew Weiner, but I can’t resist describing at least a few scenes from Sunday’s episode — including one scene that is simply one of the finest set pieces in the show’s history. (Fans are politely advised to skip ahead if they want to stay pure.)

It’s Don’s 40th birthday. He hates his birthday. (Probably because it’s not really his. Dick Whitman already turned 40, months earlier. “Don Draper,” however, was born June 1, 1926.) Megan decides to throw Don a surprise party at their new deluxe apartment in the sky, in spite of Peggy’s sage advice: “Men hate surprises. Didn’t you have ‘Lucy’ in Canada?”

She throws the party anyway. Hires a lite rock band. People sit on the floor. In the kitchen, they kvetch about Vietnam. A bit soused, Megan orders Don to sit in a chair as she cues the band and sings “Zoo Be Zoo Be Zoo” to him, a jazz-pop bit of nonsense sung by Sophia Loren. It’s nothing short of sublime, and sublimely awkward for everyone involved as Don politely grits his teeth in annoyance. “Why don’t you sing like that?” Roger Sterling (John Slattery) asks his wife. “Why don’t you look like [Don Draper]?” she retorts.

Amid all this buoyancy, “Mad Men” remains burdened, heavy. “How old are you going to be?” Bobby Draper asks his father while being dropped off after a weekend custody visit.

“Forty,” Don replies. “So when you’re 40, how old will I be?”

“You’ll be dead.”

Of the heaps of media coverage that accompanies a “Mad Men” season premiere, my favorite this time was New York magazine’s charticle in which it asked an actuary to figure out Don Draper’s probable life span.

Accounting for his legendary smoking habit, his drinking (and propensity to drive after drinking), his Korean War service, his divorce, his three children, his income ($322,000 a year in today’s dollars) the number and frequency of his sexual encounters (including prostitutes), his use of phenobarbital to combat anxiety . . . the actuary gave Don until age 59 before he keels over. That would be 1985. A particularly sharp reader left a comment hoping that Don will die while watching the Super Bowl in January 1984, just as the Orwellian commercial for the Apple Macintosh computer makes its debut.

I hope Don does get a taste of what the future brings. By the mid-’80s he will know what it’s like to feel old. He’ll know of women’s rights and workplace enlightenment, perhaps having been strung up with Dolly Parton’s “9 to 5” lasso.

But he will get out well before the real indignities begin — the automated performance reviews, the compulsory ethics and harassment training videos.

You can now feel “Mad Men” making wide circles in its flight pattern, considering its final landing in the next couple of years. (Weiner has reportedly agreed to two more seasons after this one.) It’s never too soon to think about the end in a show that encourages viewers to so torturously mull the downward spiral and the tug of mortality. It would be wonderful if “Mad Men” eventually goes out the way “Six Feet Under” did, working through a montage of the century ahead.

That would make me happy, but “Mad Men” has never been in the business of making me terribly happy. For all its power to captivate us, “Mad Men” is not really in the business of making anybody happy.

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