If you see one just domestic comedy written by an actor in the “Walking Dead” universe this winter, you might want to wait.

Weirdly, you have a couple chances to do it. “Fear the Walking Dead” star Colman Domingo’s “Dot” is playing at Park Square Theatre in St. Paul and, although it’s a fine production, the play itself is flawed. We’ll have to wait to see what the Guthrie does with “Walking Dead” star Danai Gurira’s “Familiar” in March.

“Dot” is a surprisingly conventional play, set over the days before Christmas in a Philadelphia home. That home belongs to Dotty Sheely, who is preparing to host her three adult children, as well as her son’s husband, but Dot’s cherished traditions are complicated by something that becomes clear early in the play: Dotty has a brain disease and her memory is failing quickly. Everyone else also has a secret in this overstuffed play, and we learn all of them as the Sheelys work toward a decision about caring for their mother that sounds a note of hope in the midst of a diagnosis that doesn’t offer much.

The tone of the piece occasionally seems off, particularly in the character of an unnecessary and bafflingly clueless neighbor whose main purpose is to keep saying, “I should go.” (She should.) It also goes on a scene or two too long, with an ending that doesn’t quite land.

Under E.G. Bailey’s sure-handed direction, a sharp cast gives “Dot” everything it has. Cynthia Jones-Taylor is exceptional as Dot, particularly in her navigation of her character’s mercurial moods. Even before Dotty asks her kids to play a memory-loss role-playing game, Jones-Taylor helps us understand the frustration of the disease while never losing sight of Dotty’s spirit and humor, as exemplified by this zinger about changing standards of homosexuality: “That’s how I like my gays: with handlebar mustaches and chaps.”

The best scenes in the play pair Jones-Taylor with Yvette Ganier as her eldest and most together child, Shelly (although who names a child Shelly Sheely?).

Their fast-talking, interruption-prone, we-have-had-this-conversation-a-million-times dynamic is funny and believable. But Ricardo Beaird is also terrific as Dot’s son, who has chosen the worst possible time for a juice fast.

I’ve said this before but I’ll say it again: The wild, witty vitality of Dame-Jasmine Hughes (who plays Averie, Dotty’s youngest) cannot and should not be tamed.

The action of the play isn’t always convincing, but every word out of Hughes’ mouth sounds like a blast of real.

Flaws aside, Domingo’s play shows plenty of promise. He convincingly sketches family dynamics, and the play’s abundant humor — much more than you’d anticipate when you hear it’s about Alzheimer’s — is always grounded in the specifics of the character, rather than a constant search for punchlines.

It can’t hurt that Domingo has lent conviction to all kinds of material in his acting career. That may also be why his play includes so many parts for fine actors to sink their teeth into.