Credit: Brigitte-Lacombe

Over the last several decades, playwright and filmmaker Kenneth Lonergan has earned a reputation as a sort of master miniaturist, a keenly perceptive chronicler of small, telling moments. His characters rarely live large-canvas lives; instead, they talk, meander, and double back, fumbling for ordinary truths and landing, somehow, on the profound.

The Waverly Gallery never quite builds to the emotional power of his most memorable screen work like You Can Count On Me and Manchester by the Sea; its stakes are lower, its humor quieter, and its tragedies less piercing. But it does have a movie-star cast — and a bona-fide living legend, in Elaine May — as well as a low-key, humor-laced melancholy whose impact accumulates as the play goes on.

May is Gladys Green, the kind of lady you can tell fit a lot of living into her eightysomething years before age and time started to slow her down. She lives in a Greenwich Village of indeterminate vintage (there are drug dealers on the corners still, and people say “analyst,” not “therapist”), where she’s long retired from lawyering and now runs an art gallery at the ground floor of a small hotel that mostly seems to function as a cozy extension of her living room.

It’s technically a business, though most visitors are her own family members: Her tense, nonsense-free daughter Ellen (Joan Allen); Ellen’s affable husband Howard (David Cromer); and her grandson Daniel (Lucas Hedges). At least they know who they are: “We’re liberal atheistic Upper West Side Jewish intellectuals,” Daniel explains wryly to an aspiring young artist named Don Bowman. “And we really like German choral music.”

Don, played by Michael Cera in earth-toned anoraks and a smudgy suggestion of a mustache, has come from New England to chase the New York painters’ dream, and Gladys obliges by putting him almost immediately on the gallery walls. But her mind is slipping a little further every day; at first she can’t remember names or facts, and she tends to ask the same questions over and over, amiably. Is Ellen making their dinner tonight? (Yes, just like she always does). Does Daniel enjoy his job at the newspaper? (Actually, it’s the EPA.) Can she give the dog a treat? (Never; she still needs to lose weight.) Soon, though, her forgetfulness begins to bloom into full-on dementia, moving from minor annoyance to a sort of ongoing family emergency.

May looks the part almost disconcertingly too well; she’s so small and frail, almost translucent. But the force of her personality is undiminished almost to the end: Helen might not know where she is or why her grandson seems so annoyed to answer her 3 a.m. house calls, but she wants to live. Hedges — who periodically breaks the fourth wall to fill the audience in — and Allen both inhabit their parts with tender, lived-in naturalism.

It’s Cera who feels mostly wasted in his role; he’s there, maybe, to serve as a witness, since he never quite comes alive as his own character. Lonergan seems more engaged in tracing the fear, resentment, and gallows humor that come with caring for an aging parent, and all the ways people cope, or not, with the things they can’t control. That doesn’t make for the most propulsive drama onstage, but Waverly offers something else instead: an indelibly human, quietly heartbreaking study in mortality and familial love. B+