NEW YORK, NY.- Some shows use an extended running time to challenge the audience and its perceptions. Pulling viewers into a trance state and testing their endurance is the ultimate artistic gambit.

Then there are the shows that are long simply because they have a lot to tell.

Such is the case with “Counting and Cracking,” which fills its 3 1/2 hours with an absorbing tale of family ties and national strife, from Sri Lanka to Australia, across almost five decades. When the first of two intermissions arrived, I had barely recovered from a head-spinning plot twist. And the production, which is at NYU Skirball in partnership with the Public Theater, had more in store. It’s that kind of good yarn.

Written by S. Shakthidharan, who drew from his own family history and is also credited with associate direction, “Counting and Cracking” starts in 2004 Sydney. The show opens with Radha (Nadie Kammallaweera) briskly instructing her son, 21-year-old Siddhartha (Shiv Palekar), to disperse his grandmother’s ashes in the Georges River and then immerse himself in the water, as required by tradition.

“In Tamil we don’t say goodbye,” Radha tells Siddhartha. “Only, I will go and come back.”

As the show progresses, we gradually realize what these words really mean to her, and to her family and community. In 1983, when she was pregnant and living in her home country of Sri Lanka, Radha was told that her husband, Thirru (Antonythasan Jesuthasan), had been killed in the budding civil war between the minority Tamil and the majority Sinhala. She fled the violence and settled in Australia, where she gave birth to a child who would grow up largely unaware of his heritage.

At a steady clip, Shakthidharan and director Eamon Flack (also credited with associate writing) hopscotch between Sydney and Sri Lanka from the 1950s — when the South Asian nation was still known as Ceylon — to the 1980s and 2000s and back again. Even the language is in constant movement as the 16 actors juggle English, Sinhala and Tamil, providing instant translation when necessary.

Much of Act 2 is taken up by flashbacks in which we watch the coming of age of Radha, who is played as a younger woman by Radhika Mudaliyar. The two actresses who portray Radha are particularly good at bridging the decades, and we really feel the continuity between the impetuous girl in her 20s and the sharp, loving mother she becomes.

Growing up in Sri Lanka, Radha was intellectually nurtured by her grandfather, Apah (Prakash Belawadi), a government minister dedicated to unity who finds himself increasingly isolated as nationalistic fervor grows ever more destructive on the island. Holding on to relationships is fraught: Apah calls his colleague Vinsanda (Dushan Philips) “his PF/PE — personal friend, political enemy.”

And still, Apah, who trained as a mathematician, tries to cling to the laws of algebra: “The principle of equality means that whatever is given to one side is also given to the other,” he says.

Democracy, civil war, various stages of romances, identity and language, acculturation, multigenerational tensions: It’s a lot. But unlike too many plays that feel like schematic grant proposals, “Counting and Cracking” almost never allows themes and ideas to be in the way of what happens to the people we are getting to know (the main exception is an over-explainy sequence in Act 3). For the most part, the show has a Dickensian energy, breadth and love for melodramatic revelations: We cannot wait to learn about the events of 1983, when Radha fled Sri Lanka.

What’s remarkable about the production, by Sydney-based companies Belvoir St. Theater and Kurinji, is how fluidly it moves, how much it basks in the glories of old-fashioned theatrical narration and techniques — it’s worth noting that there is no video element. (Damien Cooper did the lighting design; Anandavalli, who is Shakthidharan’s mother, is the choreographer and costume and cultural adviser.)

Time and location changes are indicated with a simple hanging sign in the back of Dale Ferguson’s sparse set. When Siddhartha and his girlfriend, Lily (Abbie-lee Lewis), go to the beach, they glide down a plastic blue tarp and are doused with water from a sand bucket labeled “wave.” At another point, a couple of actors slowly pour rice into what looks like woven trays for the sound of rain. An Australian refugee camp is economically suggested by hands reaching out of a closed gate.

When Turkish air conditioner handyman Ismet (Rodney Afif) tries to make a call on Skype (which he pronounces “Skippy”), three musicians sitting by the side of the stage play that app’s ringing tone. The frequent use of live music (composed by Stefan Gregory) — sometimes as accompaniment, sometimes as counterpoint — is one of the play’s many elements that bring to mind the vibrant work of French theater-maker Ariane Mnouchkine and her Théâtre du Soleil company. (Lucky New Yorkers may remember her epic tale of refugees, “Le Dernier Caravansérail (Odyssées),” from 2005, or “Les Éphémères,” another lengthy spectacle from 2009.)

Shakthidharan and Flack don’t exhibit Mnouchkine’s awe-inspiring mastery here, and you want them to lean even more into the theater magic they deploy so effectively. But they know how to tell a story. Which means that they know how to make us watch and hear it.

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‘Counting and Cracking’

Through Sept. 22 at NYU Skirball, Manhattan; nyuskirball.org. Running time: 3 hours, 30 minutes.

This article originally appeared in The New York Times.