True story. A stage and movie actress respected throughout the world receives an invitation out of the blue to direct Francis Poulenc’s Dialogues of the Carmelites in a second-tier European opera house. She accepts. Come awards season, she cops the national prize for best opera production of the year.

How nice for her! But in truth, the work is foolproof. Though the title sounds talky and abstruse, every production is a winner, as this month’s revival at the San Francisco Opera is all but certain to confirm. All those nuns queued up at the finale, expelled from their convent amid the anticlerical frenzy of the French Revolution, chanting the “Salve Regina” as the irregular thud of the guillotine (nothing clockwork about it) silences one voice after the other. No matter what, that ending lands, and by default it’s the director who reaps the glory. In straight theater, maybe only Peter Shaffer’s Equus—the one about the boy who blinds horses—is quite so surefire. Take a bow, George Bernanos, for your libretto after the novella of the German baroness Gertrud von Le Fort! Take a bow, Poulenc, for music that marries gripping drama to spiritual intensity!

Yet Olivier Py’s production of Dialogues of the Carmelites, now on view in San Francisco, really is something special. Like innumerable others, it is stripped down to the max. At the same time, its epiphanies of startling, solemn fantasy touch the heart with a grace hard to account for in words. Originally mounted in 2013 at the Théâtre du Châtelet, in Paris, Py’s Dialogues has won the obligatory award or three. More impressively, it has traveled widely, though never before so far afield as Baghdad by the Bay.

Crisis of faith: A severe but saintly prioress goes to meet her maker in an agony of spiritual doubt.

San Francisco Opera has a distinguished history with Poulenc’s ecclesiastical thriller. The company presented the American premiere, in English, in September 1957, a matter of months after the Italian-language world premiere at the Teatro alla Scala in Milan and the Paris premiere that promptly followed in the original French. It was Poulenc’s wish that the opera be sung in the language of its audience—a wish more honored in the breach than the observance nowadays. Sure enough, San Francisco’s current revival is its first to be sung in French, as is the global preference.

The company’s music director Eun Sun Kim conducts a promising cast. Michaela Schuster takes the brief but pivotal part of Madame de Croissy, the saintly yet severe old prioress who dies in a shocking agony of existential doubt. Heidi Stober portrays Blanche de la Force, a traumatized young noblewoman who takes the veil for all the wrong reasons. Melody Moore is Mère Marie, the nun who is spared by fate—against her will. God works in mysterious ways.

Dialogues of the Carmelites streams live on the San Francisco Opera Web site on October 21 and remains available on demand for 48 hours

Matthew Gurewitsch writes about opera and classical music for AIR MAIL. He lives in Hawaii