The Tweed Hereafter: Mr. M schools Thami.

You think, after you’ve been around for a while, that you’re immune to the small tricks. Then you’re not paying attention, and a hooky pop song sets you shimmying, or a summer thriller surprises a shriek out of you.

Or you are paying attention, to a story that begins lightly and shades into terribly dark places, and a playwright of surpassing gifts does a tiny, generous, hope-filled thing that pulls your heart into your throat.

That’s what happened to me this weekend, just when I thought I’d managed to negotiate the emotional shoals of Athol Fugard’s My Children! My Africa! The blending of a perilous historical time—1984 South Africa, not long before the six-year state of emergency—with deftly drawn, deeply individual characters is masterful. But this is what we expect from Fugard, the great bard of South Africa’s anguish. The big, passionate speeches, explaining watershed moments are lovely. But I saw the craft at work, the structural tidinesses in the script and the carefully modulated performances from Serge Seiden’s fine cast, all calculated to draw the audience in.

Then came the thing, the tiny thing, that brought all the pieces of this beautifully built play into alignment, that brought all the weight of its admirable architecture to bear. It’s just a phrase—seven little words, which you should really go and hear for yourself, that illustrate what a great-hearted, humane writer can do with the simplest of tools.

It’s an argument about the power of words that informs the play’s central conflict, between a teacher, who believes that peaceful, rational persuasion is the only way forward to a solution in South Africa, and his prize student, who, like most of the majority population, is impatient waiting for words to do their work on a minority white government that rules by force and fear.

Thami, played with an arresting blend of alert intelligence, schoolboy deference, and suppressed resentment by Yaegel T. Welch, is ready to join the radicalized comrades whose revolts and whose bombs are escalating the long struggle, and James Brown-Orleans’ magisterially proper Mr. M is frightened to the point of brusque, peremptory anger at the prospect of losing the best mind he’s ever taught.

Into the combustible center of that conflict, Fugard introduces a character who’s by turns balm and irritant—a young white woman, visiting Mr. M’s township classroom for an interschools debate, whose flashing intelligence strikes sparks against Thami’s, and whose awakening to the sense of what’s at stake for both her new friends and her country helps bring the audience along to an awareness of the same.

Veronica del Cerro’s luminously eager Isabel proves an immense asset to Serge Seiden’s admirable production; she’s urgent and brisk, full of glee at the thrill of discovering a true connection among people whose differences are all she’s been taught to know, charming even when the puckish Fugard uses her as a pinprick to deflate the comfortable condescensions of the liberal-minded.

Welch simmers at a lower, slower setting, and if there’s something a little technical, a trifle calculated about the physicality of his performance, he nonetheless gets at the righteousness of the rage boiling up within Thami’s essentially gentle spirit. And when Brown-Orleans speaks of the “whole zoo of hungry animals” inside him—of which hope, he says, is the most dangerously voracious—you understand, as clearly as you understand Thami’s choked indignation, just what the commitment to knowledge and reason has cost him.

Toward the end of the play, after a boycott has been called and broken, after stones have been thrown and names have been named, when rioters are gathering, and Thami must choose whether to stand between them and the man who’s been his mentor, Fugard gives Mr. M one of modern drama’s towering monologues, a speech about the moment he understood the immense power of ideas—about why he knows ideas and words will ultimately do more than rage and revolts. I knew that speech going in, so I was braced for its power, armed against the elegance of its metaphor and the clarity of its vision.

What I didn’t know is that it also opens the way for that little moment I mentioned earlier—that small trick, that seven-word opening toward possibility and the future, that gesture of grace and hope from a playwright who does grace and hope better than any other writer I’ve encountered—and I couldn’t know that there’s simply no defense that will do. All the limitless possibilities of human endeavor, all the countless agonies of human history, are gently cradled, illuminated in seven small words, written in the darkest days of a bloody struggle and spoken quietly to the spirit of a dead man, that contain everything: “When the spring comes—which it will.” And the only thing to do is gasp.