It must be challenging to be as fiercely talented as Danai Gurira. Or simply as fierce. Born in Iowa to parents from Zimbabwe, Gurira is a successful actress whose roles include the sword-swinging, zombie-slaughtering Michonne on TV’s “The Walking Dead” and General Okoye, the head of Wakanda’s military, in “Black Panther.” She’s also a Tony-nominated playwright whose four plays to date have been widely produced, including by Frank Theatre (“Eclipsed” in 2010) and at the Guthrie (“Familiar” in 2018).

She’s currently working on a miniseries for HBO Max. Just last week, she signed a two-year deal with ABC.

Gurira grew up in Zimbabwe but returned to the United States, earning her undergraduate degree at Macalester College. In 2016, she gave the commencement speech there.

After success with “Eclipsed,” Wendy Knox and Frank Theatre worked for eight years to secure the rights to Gurira’s play “The Convert.” Set in Zimbabwe, then called Southern Rhodesia, in the late 1890s, it’s the first play in a projected trilogy. The daughter of academics, Gurira has a deep interest in history and her own roots.

“The Convert” takes place in a single room in a small house in a city under British jurisdiction. The house was once owned by British missionaries and is furnished in the Victorian style, with carved dark wood and upholstered furniture. Now it’s occupied by Chilford (Yinka Ayinde), a Roman Catholic teacher who dreams of becoming a Jesuit priest, and Mai Tamba (Ivory Doublette), his housekeeper.

All the characters are African; all the cast is black. White characters are mentioned but never appear.

From the opening scene, we’re in another time and place. The characters converse in a mix of Shona, much of it untranslated, and English with Shona pronunciations. Ls sound like Rs, depending on how long a character has been speaking and studying English. The production staff for the play includes two Shona consultants and a dialect coach.

The shifting between languages is one of the most exciting things about “The Convert.” Kudos to the cast for making it seem so effortless; it surely wasn’t. And don’t worry, you’ll understand the gist of what’s being said in Shona, even if you don’t understand the words.

As the play begins, Mai Tamba opens the door to a young man and woman, Tamba (Maje Adams) and Jekesai (Ashe Jaafaru). They are running from Jekesai’s uncle (Warren C. Bowles). Jekesai’s father recently died, and according to tradition, Uncle is now the head of the family. He can do what he pleases with Jekesai. He plans to sell her as tenth wife to an old man who is paying the bride price in goats.

Mai Tamba is Jekesai’s aunt, and Tamba is her cousin. If Mai Tamba can talk Chilford into letting Jekesai stay on to help with the housework, Jekesai can escape the forced marriage. The catch: She must convert to Roman Catholicism and renounce her old beliefs. Also her old name. “You need a name that expresses a Christian faith,” Chilford says. He names her Ester. “You look like one – indeed you do, you do.” Just like that, with no discussion, Jekesai becomes Ester.

She evades her uncle’s grasp, learns that she’ll start school immediately, which thrills her (Shona girls didn’t go to school), and moves into a home where the floor isn’t made of cow dung. Ester is a willing student, and smart. She learns English quickly and begins converting others. To Chilford, she’s the protégé he’s been waiting for.

Beyond the walls of the little house, a rebellion has begun. The British have stolen the Africans’ lands, forced them to work in mines and treated them as savages. Uprisings are put down brutally and violently. Some Shona believe that emulating the British is the only way to succeed, to rise above their own people and gain power and prestige. Others see those who adopt white ways as “bafu” – traitors.

Gurira explores the gray areas of a black-and-white conflict. Her characters are complex and dimensional. Ester’s curiosity and intelligence shine through. Chilford admonishes her for correcting the local priest, Father Bart, when he misquotes the Bible. Ester protests and asks why, and suddenly it dawns: Because he is white. It’s her first experience of racism.

Mai Tamba is pretending to be Christian to keep her job with Chilford; Ester is not. She embraces the faith and takes seriously her charge to convert others. (She tries to convert her cousin, Tamba, and suggests “Phineas” as his new name, but he won’t have it.) Prudence (Hope Cervantes) is a sophisticated, highly educated woman who chafes at the inequality of her times. Chancellor (AJ Friday), Chilford’s friend and the man Prudence is engaged to marry, is an opportunist, an interpreter for the white mine owners, and a predator. In one of the play’s disturbing scenes, he turns his gaze on Ester.

Beneath Chilford’s insistence that the old practices and superstitions must go, and his dismissal of his country as “this land of barbarians,” his own heart is broken. He misses his family, his mother’s cooking and especially his father.

“The Convert” is somber, but it’s also very funny at times – as when Chilford comes out with an absurd malapropism, or Mai Tamba secretly conceals ritualistic items around the house, like an animal’s teeth in a drawer, or a dead snake behind the sofa cushion.

Frank Theatre, in general, doesn’t bother with trivial plays. “The Convert” has much to say about colonialism, white supremacy and the use of religion to change and fragment cultures. As it builds toward a shocking ending, which isn’t that surprising if you listen to what the characters are saying, the tension rises. And the performances – all of them – are confident and strong. Ashe Jaafaru carries much of the weight on her slender shoulders. We first saw her as the Lady in Brown in Penumbra’s 2018 revival of “for colored girls who have considered suicide/when the rainbow is enuf.” We hope to see her again soon.

Directed by Wendy Knox with her usual sure hand and humanity, “The Convert” continues at the Gremlin through March 15. FMI and tickets ($30/25).