As I made my way home from Theatre Exile’s powerful production of On the Exhale, my phone informed me that there was an “active shooter” at Pearl Harbor. When did we stop being shocked by such news? When did we learn phrases like "large-capacity magazine"?

Suli Holum begins this solo show about guns by taking a deep breath. It’s no wonder, since she will spend the next emotional hour as a woman, a single mother, who is first immersed in the paranoia of our times, and then overwhelmed by a loss beyond grieving.

Her fear begins when one of her male students — she’s a liberal college professor — refuses to revise an essay and instead attaches threatening Post-it notes to the paper. Fear becomes panic when he shows up at her office with a gun. She learns that in a newly toxic academic climate, professors lock their doors.

Her focus narrows to one question: If she dies, “Who will take care of Michael?”

Then someone with an automatic rifle shoots her son Michael and his entire second-grade class.

Playwright Martin Zimmerman imagines the trajectory of the character’s grief in remarkable ways, free of cloying sentimentality, soap-operatic clichés, or polemics.

We follow her through its stages and eventually to the gun store where the shooter bought his weapon.

To her dismay, this “merchant of death” is not an easy villain. She finds herself buying the very same automatic rifle that killed the child, and she learns to shoot. She learns that if you want to steady your aim, you need to pull the trigger “on the exhale.”

Holum performs with profound restraint. She suggests depths of feeling without overplaying them, and rivets our attention as she moves around the bare stage, under Matt Pfeiffer’s skillful and equally restrained direction.

There are overwritten moments in this short play; one could do without the “obsidian stare” of the gun. But despite the work’s brevity — On the Exhale runs for barely 70 minutes — the show amply fills an evening as it steps into the national debate about guns.

THEATER REVIEW

On the Exhale

Through Dec. 22 at Theater Exile, 1340 S. 13th St.

Tickets: $10-$40

Information: 215-218-4022 or theatreexile.org