As adult children reunite with their parents for a holiday dinner, troublesome secrets and long-held tensions surface and ignite: it’s a spectacle we’ve most likely witnessed before, in art and in life. Such a story can be funny, trenchant, and heartbreaking, and Stephen Karam’s Tony award-winning play The Humans, having its Cape Cod premiere at the Provincetown Theater through Oct. 30, is all that and more.

Karam is not interested in savaging the state of the American family, or even in creating a loving satire. The Humans is about the frailties and strengths of the Blakes, a lower-middle-class Irish clan from Scranton, Pa., with two grown daughters pursuing professional lives in New York and Philadelphia.

They struggle with each other in the great games of American life — success and self-fulfillment. Erik, the dad, is blue-collar — a facilities guy in a private school. He may be uncomfortable with introspection, but he’s no Willie Loman, tragically incapable of facing the unreality of his dreams and demons. Deirdre, the mom, is an office manager. She holds onto her mystical beliefs, religious and otherwise, with an empty-nester’s obsessiveness, and nags her daughters with criticism and cheerleading. Erik’s mom, “Momo,” has later-stage Alzheimer’s, and lives with them. They are her caregivers by default, an all-consuming task they assume with grace.

One daughter, Aimee, is a lawyer working in Philly. She’s a lesbian, which doesn’t incite parental disapproval, except for the fact that she hasn’t yet gotten married. The other daughter, Brigid, is a musician who works as a bartender in New York to make ends meet. She has just moved in with her boyfriend, Richard, to a newly rented apartment in Chinatown, a “duplex” that’s composed of one ground-floor room with a single window and bathroom, connected by a tiny stairway to a basement living room and kitchen. Richard is in his late 30s and studying for a master’s in social work. The apartment, awaiting furniture from a moving van that is overdue, echoes with disconcerting thuds and rumbles from other parts of the building. Lightbulbs keep failing. But to a couple scraping by in Manhattan, it’s home.

Brigid and Richard’s new place is where the family descends for Thanksgiving dinner. In the process of pressing each other’s buttons, each attendee reveals a major problem, mostly having to do with employment but also relationships and past mistakes. Momo, who babbles incoherently with infrequent glimmers of clarity and outbursts of terrifying frustration, is the thematic glue to all their worries: she’s a reminder of their mortality and the limits of their humanness.

Karam, who is gay and from Scranton, has said that there’s a degree of autobiography in all his work. But despite his characters’ specificity, there’s a powerful universality to the family members in The Humans, who are beautifully wrought in this Provincetown production directed by David Drake, the company’s artistic chief. The play itself is a gem. Karam has a way of eluding cloying stereotypes and making conversational speech seem unforced. Which is anything but simple: the dialogue is continually overlapping, and when emotions simmer and occasionally explode, they build organically from that complex web of talk. The action transpires in real time: scenes follow each other without blackouts or intermission. The Humans is, despite a carefully plotted structure, a slice of life.

Much of the cast is local, and all the actors triumph in challenging roles. Dian Hamilton’s Momo, for example, using little intelligible speech and feeble movements, is harrowing in a climactic scene. Ken Lockwood, as Erik, the reserved straight white patriarch, gives a remarkably sensitive performance of palpable pain and guilt and a tenacious will to overcome burdens. The sweetness of his singing voice and the emotional transparency of his eventual breakdown add dimension to his portrayal. As Aimee, the attorney daughter, Laura Scribner (who dazzled in The Lady Hamlet) is a delight: her sarcasm is pitch-perfect and her lovesickness, touching. Danica Jensen, as the host sister, Brigid, times her zingers deftly and doesn’t whitewash her character’s flaws. Even so, the daughters never seem churlish or whiny in dealing with their parents, and likewise, the parents don’t exaggerate their overbearing advice. Jadah Carroll, as Deirdre, is utterly believable as an eccentric, hardworking mom, and Nathan Butera, as the soft-spoken boyfriend Richard, is a relatable outsider confronting a tight-knit clan. All of them have good intentions, and all of their futures are coming undone.

Ellen Rousseau’s apartment set, which functions as a character within the story, is a marvel. Rousseau, credited as scenic designer and production manager, created awe-inspiring sets for the Provincetown Theater in previous seasons for Sweeney Todd and August: Osage County, and she continues to outdo herself. The play calls for two rooms on top of one another (Karam’s stage directions about the apartment are copious), which would be impractical in the Provincetown Theater’s facility. Instead, Rousseau created the rooms side by side at different heights, and the staging works stunningly well, from the sole window at far right to the kitchen at far left. Instead of feeling cramped, the set opens up the play and adds to its intricacy and complexity. It’s also a major construction project for a fringe-season show that will run only two of an originally scheduled three weeks (the first being cut by Covid issues).

Indeed, Drake’s ambition on this production is noteworthy. Karam’s writing can be daunting: the overlapping dialogue, filled with jokes and jabs, requires extraordinarily precise timing, much like farce. The action unfolding in real time, without breaks, presents additional challenges. All that is invisible in the Provincetown Theater production, which is thoroughly well-tuned. The mix of professional and community talent works like magic.

Which is why seeing The Humans in its first Cape Cod appearance in October is such a gift. Amid the otherworldly shenanigans of Halloween weekend, take the time to see a work of theater that’s indelibly real.

Duplex Dysfunction

The event: The Humans, a play by Stephen Karam
The time: Through Oct. 30, Wednesday through Saturday at 7 p.m.; Sunday at 2 p.m.
The place: Provincetown Theater, 238 Bradford St.
The cost: $40 at provincetowntheater.org or 508-487-7487