Betty and Dan, in Christian O’Reilly’s Chapatti, are worlds apart, but that doesn’t stop her.

By their pets, ye shall know them.

If so, then Dan and Betty, in Christian O’Reilly’s Chapatti, are worlds apart. She’s a cat lover with “19 and counting.” Although her marriage was brutal, she somehow has an ebullient spirit that finds humor in the strangest places. Now a senior, she care-gives for ailing, cranky friend Peggy and finds homes for boxes of kittens. Betty has never known “real” love.

Dan knew the real thing 30 years ago. That’s Martha’s faded picture in his dismal flat. When she died, a light in him went out. He says his “funny bone’s been amputated,” but it goes deeper than that. Along with a bad back from years of carpentry that restricts physical movement, Dan barricaded his heart. His only companion’s Chapatti, a 16-year-old mongrel terrier named after unleavened flatbread. They met at an Indian restaurant, where Dan fed the dog the occasional piece. If it weren’t for Chapatti, and visits to the vet, Dan would be more of a shut-in than Peggy.

Betty’s marriage had too many conditions. If she never thinks about that jerk again, fine and dandy. Dan’s love for Martha, he’s convinced, was so unconditional that surely she’s everywhere. Like a personal deity, she watches his every move, hears his every thought, and demands complete adoration. Just looking at another woman would make him unfaithful.

But wherever she is, Dan says Martha’s alone and “incomplete” without him. So why stick around? Why not find the dog a nice new home and, well, “move on”?

Christian O’Reilly’s late romance-comedy Chapatti, at the North Coast Rep, takes place in a suburb of Dublin, Ireland. Like Conor McPherson’s The Weir, which recently concluded a successful run at New Village Arts, it’s haunted. But the ghosts are different. The Weir’s at an Irish pub on a dark and stormy road. Lubricated by pints of Guinness and shots of Jameson, the denizens fully vent their pain. Chapatti’s about two people who’d never stand out in a crowd, and animals, lots of animals, and a man so haunted he can barely express himself. Dan takes his dog to the vet for human contact, not medical aid.

Few plays or movies talk about being a single senior near the point of no return (D.L. Coburn’s bleak The Gin Game comes to mind, uncomfortably). How to spend the remaining years — or months — as that big clock on the wall ticks toward midnight? Go it alone, or with a faithful pet? “Move on”? Or make one last crazy dash for love, despite a past with enough baggage to fill an airport?

Dan may be done. But Betty grows from intrepid to indomitable. Win or lose, she’ll be a player — give herself, and Dan, every chance for companionship, even if that requires a gentle exorcism.

At first, Marty Burnett’s set at the North Coast Rep looks like Dan’s image of Martha: incomplete. It’s his living room and Betty’s kitchen, a thin greenbelt down front, but no walls in between, or in the rear. Burnett has often worked wonders on the intimate stage, details in particular, so what happened?

As the play unfolds, the scenic choices make more and more sense. Chapatti is about barriers, real and self-imposed. It begins with Dan ensconced in his man cave (literally and figuratively), talking to an invisible dog; and in perky Betty’s sunlit home, where gloom needs a visa even for short visits. Nothing, visibly, stands between them — or them and us. In fact, they break the fourth wall “barrier” and talk more to the audience than to each other.

Director Judith Ivey handles what could be chaos in lesser hands. The Tony Award–winner and favorite on TV’s Designing Women makes the quirky leaps of dialogue — from them to us and back — always clear and motivated. She’s particularly deft at how Betty and Dan slowly infiltrate each other’s space. In effect, Ivey and Burnett create a Martha’s-eye view of the story. We hear their thoughts, much more eloquent to us than to each other. But we can’t see the invisible barrier that holds Dan back. He can only begin a relationship with Betty when he stops talking to Martha — and to us.

Along with being overly dogcentric (animals play a huge role throughout), Chapatti’s sketchy and at times simplistic. It wants to be upbeat but with tragic undertones, which traps Mark Bramhall’s Dan in between. He must engage with the audience yet contemplate suicide on the side. And the play often makes light of his condition (“Would you like to join me for dinner tonight,” asks Betty, “or do you have more permanent plans?”). That Bramhall builds a viable arc from the tug of depression and the pull of the comedy is quite an achievement.

The tragicomic approach lets Anabella Price shine as Betty. Still memorable for her courageous performance in the Old Globe’s Strange Snow back in the ’80s, Price gives Betty an irrepressible charm. And a sexually healthy one at that! Think senior-citizen sprite. She won’t hold back. Nor, her gleaming look suggests, should you.

• Chapatti, by Christian O’Reilly
• Directed by Judith Ivey; cast: Mark Bramhall, Annabella Price; scenic design, Marty Burnett; costumes, Elisa Benzoni; lighting, Matt Novotny; sound, Melanie Chen; props, Andrea Gutierrez