Katy Carkuff and Caroline Stefanie Clay, right, in Gidion's Knot. (Melissa Blackall Photography)

What do you do about a fifth-grade Marquis de Sade? That’s the question that playwright Johnna Adams eventually comes around to in her popular but erratic 75-minute drama “Gidion’s Knot,” now being acted with unimpeachable bite at Forum Theatre.

The play, which premiered at Shepherdstown’s Contemporary American Theater Festival in 2012 and is now making the national rounds, is a parent-teacher meeting that unfolds in real time. The single mother who shows up surprises the teacher. The appointment had been made before the boy killed himself. Surely now the meeting is moot.

But no: Corryn, the mother, arrives like a shark in Caroline Stefanie Clay’s aggressive, cold-blooded performance. As Corryn, Clay circles through Scott Hengen’s realistic classroom set in the spacious Silver Spring Black Box Theatre, tartly commenting on the student essays and mythological posters tacked to the walls. Corryn is an intellectual, a literature professor at Northwestern University; she wraps her grief in sarcasm that Clay delivers with frosty fury.

As the two characters wait in vain for the school principal, Corryn doesn’t talk — she attacks. It’s a form of bullying, for what can the hapless, guilt-stricken teacher do but sit there and take what the aggrieved mother dishes out? (As the teacher, Katy Carkuff does this deftly, keeping her head down against the gale.) And what, you may wonder during this long dramaturgical vamp, is this actually all about? What happened to the boy? Adams is irritatingly stingy with information, dribbling it out in such thimblefuls that you quickly realize she won’t reveal that critical story until the end.

The script is too coy about why the boy was suspended, why the plainly competent Corryn doesn’t know anything about it, how and why the boy killed himself — the setup just doesn’t scan, especially as Corryn keeps making stagy speeches. What Adams eventually comes around to is this: The kid wrote a searing dystopian story, a hyper-violent vision of murder and debauchery involving real students and teachers in his school.

Should this be protected as free speech and nurtured as creativity, or stifled with an instant suspension? It’s a troubling question to raise as school violence has grown alarmingly frequent and as the culture clings to more antiheroes than ever, but “Gidion’s Knot” bounces off the surface. It doesn’t dig in and dramatize with the intensity or flamboyance of Martin McDonagh’s “The Pillowman” or Doug Wright’s “Quills,” the juicy grandstanding play and 2000 film about de Sade that you may be reminded of even before Corryn says his name out loud. (The single notable lighting effect in Cristina Alicea’s staging directly recalls a stunning writing-on-the-wall effect in Woolly Mammoth’s “Quills”).

You want to give Adams credit for writing these female characters with a certain edginess, which she does in bursts. But the teacher is a traumatized wallflower and Corryn is high-handed — their exchanges are tense, but the tension is false. The real-time approach is appealing, too, but not when so much of the performance feels wasted skirting the issues; the awkward comic interludes near the end seem particularly misjudged.

The issues include whether the kid was bullied or was lashing out, whether a girl had a crush on him or whether he had a crush on a popular boy, and whether that popular boy was being abused or himself was an abuser. “Gidion’s Knot” — a co-production between Forum and Herndon’s new NextStop Theatre Company (formerly the Elden Street Players), which hosts the show starting Aug. 28 — paws at a lot of loose threads, and leaves them in a thin tangle.

‘Gidion’s Knot’

By Johnna Adams. Directed by Cristina Alicea. Lights, Paul Frydrychowski and Annmarie Castringo; costumes, Brittany Graham; sound design, Michael Dove. About 75 minutes. Through Aug. 3 at the Silver Spring Black Box Theatre, 8641 Colesville Rd. Tickets $20 to $25, with limited pay-what-you-want tickets available at the door on a first-come, first-served basis. Call 202-643-4712 or visit forum-theatre.com.