Athol Fugard’s Master Harold…and the Boys is a one-scene distillation of how institutionalized hatred—-South African apartheid, in this case—-can perpetuate itself as an omnipresent receptacle for an omnipresent substance: pain. This most openly autobiographical of Fugard’s plays shows us, over the course of a languid, rainy afternoon 60 years ago, schoolboy Hally’s close friendship with Sam, the black man roughly a generation his senior who works for his mom at her cafe, The St. George’s Park Tea Room. These circumstances, including Sam’s name and the name of the café, are verbatim from Fugard’s own life. The playwright even invited Sam Semela, the former employee of his mother’s whom he has said was his only childhood friend, to the Johannesburg premiere of Master Harold in the 1980s. Semela died before he could attend.

One problem with Bob Barlett’s initially sluggish but ultimately successful production for Quotidian Theatre is the way Ben Davis’ performance obscures Hally’s age. The script puts him at 17, which Davis alternately seems both younger and older than—-not unlike a lot of actual 17-year-olds, admittedly. Still, it muddies the dynamic between him and Sam, since we’re not sure how far each is reaching to regard the other as a peer. In Sam, Hally finds an adult who doesn’t treat him like a kid. In Hally, Sam finds a white kid who doesn’t treat him as a Kaffir—-at least not until bad news turns him petulant and vindictive.

It’s powerful stuff, once the production has balled up its fist. But it takes its time doing that, missing opportunities for comedy in the slack-paced first half. Hally casts about idly for inspiration to help him complete a homework assignment while Sam and coworker Willie (Theodore M. Snead) practice their steps for an upcoming ballroom dance contest. Their debates over who constitutes “a man of magnitudel”—-Darwin, who is Hally’s pick, or Lincoln, whom Sam prefers – or whether dance offers a suitable metaphor for geopolitics should have more snap and reverb than they do here. The good news is that as Sam, Jason B. McIntosh is sensitive and soulful, resisting any slide into Bagger Vance magical-negro platitudes. Comedy is tougher than tragedy, it’s often said, and this production could be an exhibit for the prosecution: When the going gets sad, the show gets good.

Quotidian Theatre performs Master Harold…and the Boys Friday through Sunday to April 17 at the Writer’s Center, 4508 Walsh St., Bethesda. $20-$25.