The lingering mystery of Jacy’s disappearance seeps into every inch of the novel, even as Russo builds indelible backstories for the characters she left behind.

“Chances Are …,” by Richard Russo (Random House, 320 pages, $26.95)

Early on in “Chances Are …,” Richard Russo’s riveting new puzzle box of a novel, it feels like we might be looking at a story about old guys ruminating over their life choices. And it is that, to an extent.

But typical of Russo, it quickly becomes about so much more: friendship, class conflicts, the pull of the past, the specter of Vietnam, and whether any of us ever truly change. Add in a poignant missing-person mystery that anchors the action and you have what amounts to yet another brilliant turn by Russo, as masterful as ever in creating characters that act, talk and feel like we do.

“Chances Are …” revolves around three old friends -- Lincoln, Teddy and Mickey -- onetime classmates at a small liberal arts college in Connecticut who now, at age 66, are reuniting on Martha’s Vineyard, where Lincoln has begrudgingly put his family cottage up for sale. It was in that cottage, in 1971, that they last saw their classmate Jacy, a free-spirited young woman of means with a singing voice like Grace Slick’s, with whom all three were very much in love.

The lingering mystery of Jacy’s disappearance seeps into every inch of the novel, even as Russo builds indelible backstories for the characters she left behind: notably Lincoln, the risk-averse commercial real estate agent who essentially “opted out” of the ’60s counterculture, and Teddy, an anxiety-prone academic with a secret of his own.

Russo spends a good chunk of the novel shifting perspectives between the two men, following them through flashbacks from childhood through their college days and the key events that led to their current-day reunion, in a way that makes both the men and their friendship seem gloriously real. (Russo remains a master of portraying characters at different stages of their lives, and making them feel like equally compelling versions of the person we’ve gotten to know.)

Frustratingly, though, we’re left for a time without the same insights into the characters we’re most curious about: roughhousing rocker Teddy and, especially, Jacy, who feels like she might end up more of a cipher around which the men’s hopes and desires hinge rather than a real human being. That’s until about two-thirds of the way through, when Russo turns his attentions to that pair and fills in their blanks with touching and heartbreaking details that are worth the wait.

Some of those details involve the aforementioned life choices, a favorite theme of Russo’s. In 2007’s sprawling “Bridge of Sighs,” he compared them to multiple doors that lock behind you every time you go through one; here he likens them to your view through opposing ends of the telescope. In both cases the characters fall victim to blissful and sometimes willful ignorance before making the best of the hands they’re dealt.

And as they do, they’re surrounded by an orbit of characters that are among Russo’s most absorbing featured players, including the retired police chief with his own reasons for taking up Jacy’s decades-old mystery, and the rogue’s gallery of parents whose sometimes comic, sometimes terrible histories are woven expertly into the narrative and explain so much of what the main characters become.

To give away any more would be unfair, but I will say that like in most Russo novels, he’s refreshingly unafraid to provide an ending that, if not entirely “happy,” per se, is unflaggingly satisfying. If that means a few of the loose ends get wrapped up a little too patly, so be it: Thanks to Russo’s diligence as an author, whatever hope the characters manage to find feels well-earned.

Peter Chianca writes about Bruce Springsteen for Blogness on the Edge of Town and about numerous other subjects for GateHouse Media. Email him at pchianca@wickedlocal.com.