Last year, playwright Alexa Derman ’19 workshopped “Why We Have Winter” in a rickety, cuboid L-Dub suite. It was an informal affair, with snacks (cheese and crackers) and an audience sitting cross-legged on a hardwood floor. Now “Winter’s” a full-fledged production, directed by Michaela Johnson ’17 and starring four very talented actors. It’s come a long way from its origins.

Put on by a production staff of entirely female and non-binary individuals, “Winter” follows Anna and Helen, a same-sex couple in their last year of high school grappling with the fallout from a party where Anna was sexually assaulted in a bathroom. Along with fellow students Jeremy and Peter, the two are putting on a play about the abduction of Persephone, a myth with obvious symbolic value considering their current circumstances.

“Winter’s” focus is not chiefly narrative. It’s a post play, in that it deals with aftermath rather than event. However, the dialogue is so airtight and the prevailing mood of desperation so well painted that the production rarely sags. The raw emotional intensity of the situation is never cheapened by cliche or sentimentality (an enormous danger, especially when dealing with topics as weighty as those tackled here). Derman depicts the characters with enormous sympathy; one can identify with both Helen and Anna, even when they’re at odds.

At times, “Winter,” like “The Glass Menagerie,” feels like an extended expiation of guilt. Played by Isabella Giovannini ’18, Helen is the production’s main character; the play dwells on her contradictory emotions as she struggles with and is occasionally overwhelmed by the pressure of being both partner and caretaker to an emotionally and sexually unavailable Anna.

Derman has a real ear for the language of evasion, and her dialogue often recalls “Hills Like White Elephants” in the way it revolves around and around and around a gravitationally attractive topic without ever getting anywhere. Three of the four characters riff in the effusive mode reminiscent of upper-middle-class teenagers involved in theater, and the verbiage of early scenes can test one’s patience with torrents of pop culture references and millennial irony that gradually grows grating. However, as the horrifying specifics of the situation become clearer and clearer, this concern becomes irrelevant and the joking and deflection acquire an aching sadness.

It’s tempting, as a reviewer, to vacillate back and forth between different poles of extremity, to shriek either praise or opprobrium from the rafters. Nobody wants to read or to write a middling evaluation. The prevalence of declamatory reviews may mean that the following isn’t taken with much seriousness. But at this moment, I truly mean it when I say that this, friends, may be something along the lines of a capital E Event. “Winter” is an urgent play of lacerating anger and quiet pathos, genuinely affecting and devastating in its emotional impact. I left reeling. It’s a play our campus needs right now, and I might even venture to say that it’s the best student production I’ve seen over the last two years.

Correction, April 23: A previous version of this article misstated the name of a character who was assaulted.