When was the last time you heard the word "midlife" without the word "crisis" attached? Put a few fortysomething friends in a dining room, and sooner or later someone will start complaining. Balancing a career and child-rearing is so tough! The thrill has gone out of our sex life! This risotto is overcooked!

At its lowest point, the midlife crisis can be summed up in one devastating line: "He's leaving me."

So begins Dinner With Friends, which earned playwright Donald Margulies a Pulitzer Prize in 2000. The current production at Town Hall Theater is the Middlebury Actors Workshop's first full-length play after four summer seasons of short, predominantly comic works.

Dinner With Friends is also a departure for MAW in that it mixes comic elements into a provocative dramatic meditation on not merely the moral implications of marriages and breakups, but on the costs and benefits of staying or straying. Its cast members master the material with often-painful precision. And, behind the scenes, MAW is a theater troupe for which the play's themes are potent metaphors.

Dinner With Friends begins in the home of Gabe and Karen, husband-and-wife food writers played by Richard Steggerda and Jeanne Rogow. As they host old friend Beth, an artist played by Karen Lefkoe, they natter on about a recent trip to Italy. Beth is clearly not paying attention and, as dessert is about to be served, she breaks down. Her husband, Tom, is having an affair with a stewardess, she tells them. He's leaving her.

What follows is a series of scenes exploring the relationships that bind the four characters together -- as friends, lovers, spouses and... whatever they are now to become to one another. Each connection is suddenly strained. Tom, a lawyer played by Mike Kiernan, feels compelled to argue his case before Karen and Gabe, having lost "the advantage" to Beth. Their friends have only heard her side of the story.

The congenial Gabe, though plenty perplexed by his friend's affair, bristles at his wife's indifference to Tom's explanation. A few moments later, Tom chafes at Gabe's suggestion that he's making a mistake by ending his marriage. In a later scene, Karen questions the choices Beth has made in her newly single life -- unwelcome advice, as it turns out. Two pivotal scenes find Gabe and Karen contemplating where their own steadfastness has led them.

The play's simple form and spare settings allow MAW director Henry McEn-erny to mine the emotional depths of each scene. The easy interplay of friends and spouses engenders a compelling ambiguity about who is better off for the decisions he or she has made. When Tom, for example, describes his sexual relationship with his new lover, envy quickly but undeniably flickers across Gabe's face. At one point, Karen and Gabe concur that both Tom and Beth look better, and more fit, for having separated.

Personal disclosures also lend scenes dramatic punch, as when Beth reveals to Karen what she's really thought of her all these years, and when Tom tells Gabe how he really felt those many summer weekends their families spent together. This is a genuinely discomfiting work -- but not because of strong language or shocking situations. Rather, the truths revealed moment to moment illuminate what close friends think and feel but rarely say to one another, unless moved by some crisis.

The resulting play is as resonant as it is realistic. "Everybody knows somebody in the play," says Steggerda after a recent rehearsal. "People are going to identify with each of the characters."

No doubt the marital discord will resonate with some, marital monotony with others. And certainly many will, as Rogow's character notes, see their lives in terms of how much has passed and how little remains. "You don't have this scope of infinite possibility in your middle life," she says.

The play's resonance with fortysomethings in particular hits close to home for this troupe. The typical upstart theater company is composed of young actors, fresh out of college or acting school. MAW's youngest member, Lefkoe, is 39, and everyone in the troupe has assumed the adult responsibilities that usually extinguish one's acting dreams. While their professional acting credentials are substantial, these players have other careers now -- and mortgages, children and parents in their sunset years. "People just have busy, complicated lives," Rogow says.

And the hectic pace of middle-aged life presents a specific casting challenge. "We're always looking for a few good men," she says. "It's harder to find men of a certain age."

Rogow believes the play relates one's personal sense of security to the larger state of the world. "I felt like this is the time to do something like this," she says. "We all get really fragile about our existence...I think all of us are feeling that way as the world is getting more and more precarious. There's something really scary about needing to sit with uncertainty and to be OK with it, and I think these are uncertain times. This play is, I think, a metaphor for that."

Whatever individual cast members draw on in performing, it's working. McEnerny has guided his cast toward a convincing on-stage chemistry. Steggerda's Gabe is a dutiful husband and father whose pleasant demeanor juxtaposes well with Rogow's more assertive Karen. The actors make it easy to imagine their characters as writers and spouses. Indeed, there's a subtle routine about everything they do together that, over the course of the play, adds up to some poignant conclusions about their marriage -- about marriage, period.

Steggerda turns in an especially nuanced performance, hitting notes that range from obedient errand-runner to stalwart old chum, to a deeply introspective man grappling with the inevitability of the kind of life he and Karen have settled into. It's a life they certainly never envisioned for themselves. Rogow is also a strong, confident presence, playing a borderline control freak and zealous foodie but also revealing, in glimmers of wounded self-honesty, that she, too, has doubts about where things stand in her life.

As estranged couple Tom and Beth, Kiernan and Lefkoe do a fine job of dramatizing the characteristics that suggest they probably started out as good candidates for divorce. There is something dull about Kiernan's Tom -- a touch too much of the man's man. "Rage can be an amazing aphrodisiac," he says to Gabe shortly after throwing his weight around in a bedroom confrontation with Beth. In the end, Tom's physicality and conventional male attitudes fail to mesh with Beth's flightier artist's temperament. Lefkoe rises admirably to her role's greatest challenge in conveying the hurt she has experienced at Tom's hands. Lefkoe admits she had to reach to bring out Beth's neurotic side. "It's tough to start a play at such a low point," she adds.

On opening night, the cast struggled to maintain optimal stage volume, and the Town Hall Theater's resident bat threatened to upstage everyone during its usual second-act appearance. Overall, though, MAW and Dinner With Friends proved to be a good match -- albeit one that, like any relationship, requires some work.