The looming shadow of the AIDS crisis hangs over Terrence McNally’s latest play, Mothers and Sons. When the curtain goes up, we’re in Cal’s apartment on Central Park West. Cal (Frederick Weller) and Katharine (Tyne Daly), the mother of his late partner Andre, are at the picture window discussing the view — the apartment building across the way where Jackie Kennedy once lived but also the site of Andre’s memorial in the park, where the jokes were perhaps “too gay” for Katharine in stark contrast with the somber tone of the operatic Mozart piece, “L’ameró saro costante,” that one of her son’s friends had sung earlier that day at the church.

McNally, one of the fiercest and most prolific chroniclers of gay life in the U.S., keeps his characters dancing on eggshells. Katharine, who has stopped by unannounced to return her son’s journal (still unread) to Cal, is one icy dame. Reluctant to let go of her grief, she’s carried the pain of her loss along with her over the twenty years since her son’s death with unwavering constancy. Still, she’s human, and the chinks in her armor begin to widen as the play progresses and Cal and his younger husband Will (Bobby Steggert) and especially their son Bud (Grayson Taylor) show Katharine the not-so-unique facets of their family bond.

Daly is the primary reason to see the play, which is a fine but flawed piece of work. She’s a force of nature as Katharine, the gorgon with a hidden heart, quick-witted but with a sense of unclaimed selfhood that’s held her back throughout her life, not just following the death of her son. Weller as Cal is a competent match for Ms. Daly, full of fond memories of Andre and increasingly insensitive to Katharine’s lingering intolerance. Bobby Steggert as Will and Grayson Taylor as Bud are also fine additions to the cast.

The play, which utilizes the Classical unities by presenting its action in real time over the course of ninety minutes, strains credulity at times. As was the case in the masterful comedy God of Carnage, which trapped four parents in one room for the same duration, one never quite shakes the sense that Katharine stays in Cal’s apartment beyond the length of time any woman in her situation would. Along the same lines, as emotions bubble over in the play’s second half McNally’s talents buckle under the weight of the marks he hopes to hit along the way. There are several beautiful monologues, but a few of them feel somehow unearned within the context of the plot, existing more to tick off McNally’s ideological bullet points than to serve his characters.

Flaws and all, Mothers and Sons packs quite a punch. Despite taking place in a beautiful bourgeois apartment (the set has been realized by John Lee Beatty with great attention to detail) in a  condensed amount of time, it never bores thanks primarily to McNally’s passion for his subjects. Daly and Weller in particular give such textured performances that I (and a good many of my fellow audience members) were in tears by its final moments, in which a simple hug can elicit an outpouring of emotion thanks to Sheryl Kaller’s sensitive direction.

What we’re left with is a sense of the universal that’s inherent in the personal lives of these characters. All (or at least the vast majority) of us can relate — if not to motherhood then to having a mother. And all of us can at least imagine the sense of loss at being predeceased, either by one’s child or the love of one’s life. For those of us who came to New York after the toughest surge of the AIDS crisis had subsided, the play highlights, in a similar way to Larry Kramer’s The Normal Heart, the losses we’ll never be able to quantify.

Toward the end of the play, Cal underscores the vast changes for gays in this country since 1994. Where the words “lover,” “partner,” and “boyfriend” used to vie for prominence, “husband” has now climbed the ranks (the play represents the first legally married gay characters on a Broadway stage). Where a family with two gay patriarchs was a near-impossibility, it’s now an ogled-but-increasingly-commonplace anomaly. Trailing along behind the vast improvements for the gay community like the clanking cans behind a newlywed’s car are the individual losses, like Katharine’s and Cal’s, that defined an era of uneasy progress. For her, being Katharine always played second fiddle to being “Andre’s mother.” Even now, she shudders when Cal mentions that her son’s name is included in the AIDS memorial quilt.

“I know what loss means,” she says near the play’s end. “Try to respect Cal’s,” Will replies. “He lost more than your son. He lost a generation.” Katharine craves retribution; she goes so far as to proclaim her desire for revenge. But to a generation numbed by enduring loss, the blunt edges of revenge dulled early on. Cal’s present circumstances — his family — may not have replaced Andre, but they have helped to fill in the hole where his loss once was (and still is sometimes). For Cal, and for many of his generation, that’s all he can ask for, and even Katharine — who, tragically, never quite found her own saving grace — can’t take that away.