Put two actors on an all-but-bare stage in a tiny, exposed theatrical space, and it doesn't take long to see whether they're artistically in tune. Mphela Makgoba and Doug Brown, the fine duo who portray anguished political prisoners in the American Showcase Theatre's production of Athol Fugard's "The Island," begin the evening grunting, gasping and dragging imaginary wheelbarrows across an invisible beach. Handcuffed together, they run feverishly round and round, goaded by an unseen but terrifying warden. Thrown into the cagelike quarters they share, Winston (Brown) falls to the floor, writhing and moaning in pain. John (Makgoba) flings his urine into his cellmate's injured eye, as if to simultaneously cleanse the wound and divert the sufferer.

In those first, wordless minutes, an intense relationship is forged, a powerful mood has been created. They have sucked us into the bleak, unjust world of Robben's Island, the South African maximum security prison to which scores of anti-apartheid activists have been exiled. And once Fugard's language -- a riveting mix of invective and poetry -- gives voice to the pair's individual and collective frustrations, that world becomes even more credible.

An odd couple indeed, wise John and his younger, raging associate Winston spend their time bickering, joking, salving each other's spirits and rehearsing their parts for "Antigone." Yes, "Antigone." It seems that the prisoners are to have an informal, in-house performance, and John (and the playwright) is dead set on pointing out that the plight of Sophocles' embattled heroine is very similar to their own. Winston, not the most intellectual of men, can't get beyond the fact that, as Antigone, he must don a wig and false "titties." If there's one thing he can't abide, it's people laughing at him. In the end, however, the show goes on, with Winston and Antigone merging into one potent and eloquent force.

Brown does a masterly job of communicating his character's anger, humiliation and, eventually, empowerment. A compact powder keg of a man, he brings us to the brink, then recedes. When he speaks about his cellmate's fast-approaching parole, one can almost taste the venom on his tongue. And when he finally breaks through his wall of despair, you feel a leader being born.

With his bottomless bass voice and rubbery, ever-changing countenance, Makgoba is the showier presence. One moment he's a wizened wreck, next he's a sage elder, and his on-the-mark portrayal of King Creon, Antigone's vile uncle, is all strut and pontification. He's also done a first-rate job as director of the production. After reading his biography, this comes as no surprise: A veteran actor, singer and director both in his native Johannesburg and, since 1964, in this country, he has waged an ongoing struggle -- both in his art and life -- against the evils of apartheid.

The Island, by Athol Fugard, John Kani and Winston Ntshona. Direction, lighting, sound, set and costume design by Mphela Makgoba. With Doug Brown and Mphela Makgoba. At the American Showcase Theatre through Feb. 10.