Thirty years ago, I spent all the money I had on two purchases: The first was a top-of-the-line Brother typewriter for $800. The second was an engagement ring for $425. When my future mother-in-law saw the diamond, she said, “Wait a minute, I need my glasses.” But my fiancee wasn’t troubled by the size of the stone or even by the cost of my typewriter. And in any case, she got the last laugh: My Brother is long gone; my wife is still here.

As you probably know, “A diamond is forever.”

What you may not know is that a young woman came up with that phrase in 1947 while working on an ad campaign for De Beers. Frances Gerety was a copywriter for N.W. Ayer & Son, the late, great Philadelphia advertising firm that taught us to “Reach out and touch someone” and “Walk a mile for a Camel.” Gerety’s diamond tag line was the firm’s masterpiece; Advertising Age crowned it the best slogan of the 20th century. (Take that, Don Draper!) Ironically, Gerety herself never married (neither did De Beers’s founder, Cecil Rhodes), but she and her ads crystallized an engagement expectation made from the hardest substance known to man: tradition.

Gerety’s life is the historical spine that runs through several fictional stories in J. Courtney Sullivan’s third novel, “The Engagements.” This is “Mad Men” before the men moved to Madison Avenue, and Sullivan captures the postwar workplace in all its crisp formalities and crude prejudices. Frances is a rare woman in a chauvinistic industry dedicated to promoting consumer roles for breadwinner and homemaker. She leans in with everything she’s got, but the old boys still treat her like a super secretary. It’s a perceptive portrait of a talented woman too wise to grow bitter, but too smart to ignore the truth.

While Frances hawks diamonds to a country that doesn’t yet know how much it wants them, “The Engagements” constantly shifts to other, less mercantile facets of romance. Like a wedding planner managing five demanding clients, Sullivan rotates, chapter by chapter, over 80 years of love, American style. From the 1930s to 2012, from chaperoned dances to, we see attitudes about relationships solidify, dissolve and reform. Some of these couples polish their devotion to a blinding sheen, some trample on their vows, and still others dare to construct something new from something old. But through it all rolls the ring adorned with a diamond — a cartel’s best friend. In Sullivan’s easy, unadorned style, “The Engagements” is a delightful marriage of cultural research and literary entertainment — the perfect book to ruin your wedding plans.

It’s hard to describe “The Engagements” without making it sound like a lot of clunky exposition and domestic construction: five settings, dozens of characters, and all the attendant social and political contexts that need to be built for these separate plots. Don’t worry: Even jumping from story to story every few pages, Sullivan handles all the details elegantly, and the situations are surprisingly distinct, adorned with the unique elements of the times and even the disparate ways people spoke:

●A paramedic in Boston struggles to provide for his wife on Christmas.

●A wealthy, older woman can’t imagine why her ne’er-do-well son wants to abandon his wife.

●An antiques dealer from Paris destroys her cheating fiance’s apartment.

●A woman who disdains marriage must plan her gay cousin’s wedding.

Each of these stories explores the way lovers express their affections — how they worship fidelity or rationalize infidelity as Time’s winged chariot hurries near. And as we follow them, the sparkle of that diamond ring keeps catching our eye until finally, subtly, all these characters are wedded together.

Despite Sullivan’s portrayal of what motivates lovers, her stories remain, to a striking degree, as prim as a De Beers ad. In a series of otherwise psychologically astute character studies, she gives us intimacy almost completely devoid of sexual desire, fulfillment or frustration. Instead, 45 years after John Updike’s Couples,” this new novel about coupling titillates us with just the explicit mechanics of advertising. And, I have to admit, the stories never grow flaccid. Perhaps in a market-obsessed culture, nothing is sexier than marketing. Not tonight, dear, I have a spreadsheet.

’The Engagements’ by J. Courtney Sullivan (Knopf. 383 pp. $26.95) (Knopf)

But for a novel that presumes to examine a swath of marriage experiences in the 20th and 21st century, the curious thing is who’s not invited. In these pages, the bride must not only wear white, she must be white. Without insisting on a Benetton spectrum of diversity, it would have been nice to consider how marriage rituals, wedding expectations and corporate advertising play out among African Americans, for instance, or Hispanics — anything to add a little hue to this monochromatic survey.

But I can feel relatives glaring at me, so let’s move on. This is a reception, after all. And Sullivan is at her best when cataloguing the obscene excesses of the modern wedding ceremony. One of her characters, Kate, a granola liberal whose self-righteousness could cut glass, fumes at the extravagance of her cousin’s nuptials. Don’t invite Kate to your bachelorette party: Amid the fittings and the tastings and other preparations, she lectures anyone who will listen about the evils of blood diamonds. She’s struggling to raise her daughter on organic yogurt and total gender equality, but that’s hard in a world where loved ones insist that the shape of your diamond “says a lot about you.”

As these blessed and disastrous relationships play out across the decades, Sullivan returns again and again to the clever work of Frances Gerety and her campaign to make everyone believe that men have always given their fiancees diamond engagement rings. Every time incomes rise or fall, or new mines are discovered, or courtship attitudes shift, the Ayer agency adjusts its tune to keep American brides walking down the aisle with little chips of compressed carbon on their hands. Times change, but

Examining these characters through Sullivan’s loupe, it’s impossible not to consider your own attitudes about engagement rituals. Gerety’s ads have infected us all with the tyrannical standard of the perfect will-you-marry-me moment. Who can resist feeling that the size of the gem reflects the depth of a man’s adoration? Subjected to the right propaganda, how quickly traditions can be manufactured and given the patina of age. But here’s a novel that could save you thousands of dollars. If you’re in the market for a ring, don’t worry about what the ads call the 4 C’s: cut, clarity, color and carat. It turns out, that’s all 1 C: crap. As Sullivan makes plain, whether or not your marriage gets off to a good start has nothing to do with your gemstone investment.

I’m not giving anything away by revealing that “The Engagements” ends with a wedding. An engagement ring, after all, is like Chekhov’s gun: If we see it in the first act, it had better be used by the time the curtain falls. And for all her sharp wit and insight into the agony of failed relationships, Sullivan’s no cynic. The novel’s final wedding transcends the craziness and the extravagance and the bickering. Against all odds, it represents something genuinely eternal about the love between two people.

Do I believe in that?

I do.

Charles is the fiction editor of The Washington Post. You can follow him on Twitter: @RonCharles.


By J. Courtney Sullivan

Knopf. 383 pp. $26.95