Two lives, far apart and close together

Lindsey McWhorter (front) and Ramona Lisa Alexander in a scene from ''In the Continuum.'' (CRAIG BAILEY/PERSPECTIVE PHOTO)

"In the Continuum," a story of two unforgettable fictional women, grew out of the collaboration of two equally unforgettable real women.

Danai Gurira and Nikkole Salter met as graduate acting students at New York University, where each was creating a monologue about a woman infected with HIV, the AIDS virus. They combined the two stories and went on to perform the resulting play in New York and around the world.

In their performance, which I saw at New Haven's Yale Repertory Theatre in 2007, "In the Continuum" was an astonishing piece of work. Profoundly political in its comprehension of the gender and class issues that affect many women of color living with AIDS, it expressed this comprehension through the expert interweaving of two carefully wrought individual stories: one of a troubled teenager in South Central Los Angeles, the other of a successful newswoman in Zimbabwe, both of whom have just discovered that they are pregnant and have been infected by the men they love.

It was breathtaking, both emotionally and intellectually. But when news came that the small Boston company Up You Mighty Race would be staging "In the Continuum," with its own cast and director, to open its first season as a resident company at the Boston Center for the Arts, I worried that this play could not possibly have the same force and beauty without its creators performing it, and that this ambitious plan was simply too ambitious to succeed.

I'm thrilled to report that I was wrong. Akiba Abaka, the director and guiding spirit of Up You Mighty Race, has staged "In the Continuum" with clarity and grace, and the two women on her bare stage, Ramona Lisa Alexander and Lindsey McWhorter, create performances of seemingly effortless virtuosity and heart. The power that before might have seemed partly the result of watching a play's creators enact it is here revealed for what it is: the simple, ineluctable strength of an authentic work of art.

Alexander, who plays the teenaged Nia, and McWhorter, who plays the adult Abigail, also take on a host of other roles: nurses, friends, family members, social workers, and others who round out the stories of these two strong, scared, unlucky women. The actresses shift seamlessly from one persona to the next, with nothing more than a few simple costume changes to support the vividness of their characterizations in vocal pattern, attitude, and gesture.

Abigail and Nia, living on opposite sides of the world, are just as far apart in circumstance and life experience. Abigail is married, the mother of a young son, and a hardworking professional woman; Nia lives in some kind of foster care, has had a few brushes with the law, and fantasizes that her boyfriend will make it to the NBA and take her along with him to Easy Street.

McWhorter and Alexander bring these women to life with specificity and warmth. Nia and Abigail are both tough, funny, and full of life, and the breadth and depth of their personalities put an unforgettably human face on the larger social concerns of the play. (Up You Mighty Race, by the way, is admirably probing those concerns with a series of talkbacks about various aspects of the AIDS crisis after every Friday night performance.) They're not saints, either, and their occasional weaknesses only deepen our understanding of them and our longing for their lives to turn out better than they probably will.

Akiba's staging is generally clear and clean, with a few simple projections on the floor of the Plaza Black Box providing the only setting. A couple of her ideas muddle things a bit, as when in parallel scenes with the women riding in a car she has the actresses roll their arms around like giant wheels. She also has them move directly into the seats that surround the playing space on all four sides, a choice that can feel a little too intimate when, as happened the day I was there, only one or two people are sitting in a row.

But that's a problem that this production doesn't deserve to have. "In the Continuum" is a play that cries to be seen - and one that richly rewards those who heed the call. May it be the first of many Up You Mighty Race productions that fill the BCA's theaters to the brim.

Louise Kennedy can be reached at kennedy@globe.com.