On the Exhale (2017), now running at Theater With a View on Sycamore Hill Estate in Pottstown, is an advocacy drama about American gun violence. But playwright Martín Zimmerman's powerful 60-minute, one-person play does not preach. Rather, it invites you to empathize with its sole character, an unnamed woman whose only son is slain at an elementary school, in Columbine fashion.

Executive director and actress Nina Covalesky turns in a mesmerizing performance. She never hams up the mother's distress. But as random waves of anger, despair, and self-bemusement wash over her face and subtly inform bodily movement, you never doubt this character is a real, suffering person.

With Proustian detail, the grieving woman is both deeply introspective and acutely aware of the falsity of others. Their sympathy suggests a subscript demand for her to be sensible. But in talking to us, this mother is neither seeking exorcism nor trying to bring her suffering to "closure." She wants to take possession of it.

One reason Exhale hits hard is that you come to know her so well before tragedy strikes. As a university professor, she has a recurring nightmare involving a gun-wielding student, in which assailant, victim, and weapon merge in an "obsidian stare." She succumbs to fear, keeps her study room locked. You also learn she is a single mom by choice and has a dicey relationship with her community.

Love for her son is all she has. When he is killed, her nightmare becomes real, her isolation more intense. Though her flux of thought and feelings is wild, they are still consistent with the personality you have already come to know. Her actions are unpredictable, but when she does act it makes a kind of crazy, perfect sense.

The woman is full of surprises. You never expect her to visit a gun shop, then find the owner to be so grandfatherly. Or that she will develop a relationship with an assault rifle. Her estrangement at a congressional hearing and tragicomic hook-up with a gun-rights politician is worth the price of admission.

Theater With a View is an open-air venue, and director Elaina DiMonaco's stagecraft is spare, using only Toby Pettit's ominous sound design to underscore the monologue. Her show is a triumph of advocacy theater, a tribute to both playwright and performer.

Footnote: The theater will donate $1 from every ticket to Everytown for Gun Safety, an organization with four million members. You can learn more about them at www.everytown.org.