The set for Bo-Nita: A Play Performed by One Woman is a fake-out. At first, it looks like the oppressive, brutalist exterior wall of an urban American high school—it's as implacable as a cliff, with slab-like buttresses at the top angling out toward the audience, threatening to crush the well-dressed people in the first few rows. Its color is a Rothko-style study in baby-shit yellow, mottled with swaths of white, as if somebody has used a paint roller to cover up graffiti. A large basketball backboard hangs in the middle of the wall, its hoop sagging like a slacked jaw.

There's one sign of life on stage—tucked up in a corner, sitting on the ground behind a bicycle rack, a girl reading a book. Meet Bo-Nita, a 13-year-old who wears lots of layers: blue jeans with cuffs frayed at the heels, a baby-doll dress over the jeans, a hoodie over the dress, and plastic barrettes in her hair. She looks trapped and tiny in this concrete canyon. As she stands up, looks around, and steps forward to address us ("There's this guy... he's like my... well, this guy, you know?"), we realize that this set, designed by Jen Zeyl, is really just a blank canvas. Even though it doesn't have any trapdoors or rotating platforms or other tricks—it doesn't physically change at all—it becomes wherever Bo-Nita needs it to be as she tells us her epic, winding story about what happened when her mom's ex-husband was trying to beat her, and perhaps to rape her, and then had a heart attack.

Written by Seattle playwright Elizabeth Heffron, directed by Paul Budraitis, and performed by Cornish graduate Hannah Mootz, the talent behind Bo-Nita is about as local as it gets. But the story—about the vulnerability and rage of a young girl, and how she uses humor to cope with her thorny, dangerous world—could be from anywhere.

Bo-Nita's story begins with Gerard, her mother's ex-husband (who's part Cajun) writhing on the floor, begging Bo-Nita to fetch him some nitroglycerin from the medicine chest for his sudden heart failure. "He keeps working this whole 'life' deal," Bo-Nita tells us in an eye-rolling tone of voice, "fighting for all the angles, hoping I'd just forget the pounding he was about to give me for having a smartass mouth—'cause I joked about him not being able to get it up to poke me. Like I was gonna go get his nitro!? No way, sucker, writhe!"

Once Gerard is safely passed out, Bo-Nita is seized with a sudden fury, flies off her bunk bed, and beats his unconscious face into an actual pulp. Mom shows up a few moments later, drunk, with a new boyfriend in tow (Bo-Nita dubs him "Whozzits Number 47"), and then everybody's got a problem. Bo-Nita could be accused of killing Gerard, mom's already in a tenuous legal and child-custody situation, and Number 47 is married and doesn't want any public controversy to pin him at the scene. They've got to get rid of the body.

The rest of this grim caper, with its footnotes and asides, becomes the vehicle for Bo-Nita to tell us about her life while acting out half a dozen characters on the way: her waitress mother; her stoner, exotic-dancing grandmother; the grandmother's pot-dealing brother; Gerard, who has abused her but also been a sort of mentor; Gerard's even-more-Cajun uncle; and the shocked and twitchy Number 47, a tile salesman.

Mootz flies through all these characters like an ace pilot, sometimes playing four of them all fighting each other at once. Like the set, the story is deceptive. On its face, Bo-Nita is a body-disposal-adventure comedy of errors, at times with the frenetic, gallows-humor energy of a Quentin Tarantino film. But it's wrenching the way Bo-Nita casually drops small details—about her grandmother's cancer, her mother's string of bad boyfriends and prison time, the restraining order they had to get against Gerard—before skipping on to the next colorful anecdote. Cancer, a jailbird mom, and child molestation are simply the contours of her life, not anything she dwells on for too long. Their very unremarkable-ness to Bo-Nita is what makes them, for her listeners, so painful to hear. But while the details jerk us from comedy to tragedy and back again, the story flows out of Mootz with the seamless, high-energy patter of a preadolescent who just wants someone to listen to her, on her terms for a change.

Heffron says she started Bo-Nita in 2008, after her first regional-theater production, Mitzi's Abortion, at ACT Theatre. Like Bo-Nita, Abortion navigated tough social terrain by sticking to the absurdity of its characters' situations and their senses of humor. She had started working on a play about the Hanford Nuclear Reservation and was doing intensive research about nuclear waste.

"I thought, 'I can't take this anymore,'" Heffron said, "so I'd sneak over and secretly work on Bo-Nita. The funny stuff came first because the nuclear stuff was so dark."

It began as a play for at least five actors, but she realized the story would be told best if it all happened in Bo-Nita's mind. "Letting it be so female was helpful," she said. "That's the voice—it's just the girl. And about the ambivalent way life puts people in the world. How the people who can help you can also hurt you."

That ambivalence is at the center of Bo-Nita's complicated relationship with her mother and with Gerard. She has affection for him, as well as the conversations and fun they've had over the years, but he's also abused her. Heffron, and Bo-Nita, won't allow us to dismiss him as a simple monster, but he's not a good guy either. "Young women are just so unprotected," Heffron said. "You go through life and those things happen—that level of danger you're unaware of until things get really crazy. I think that stuff happens so much more than people realize."

For that reason, Heffron's work makes a point of tangling the human side of a story with its broader social and political implications. She worked for several years teaching in a women's prison and saw how tough it is for ex-con single moms, especially in a climate that wants to cut social-services programs for people like Bo-Nita and her mother.

"It makes me furious when people talk about how much money it costs," she said. "It's like: 'What are you talking about? These are our future citizens.' I just find that so naive and stupid. For me, the goal was to tell a human story about the harshness of capitalism, and ask what really is a social safety net?" Especially a safety net that looks like Bo-Nita's.

The magic of Heffron's writing—and Mootz's performance and Budraitis's direction—is its deftness, its ability to slip these bitter questions into a story that is, despite itself, still funny. Bo-Nita, like its title character, is a little miracle. recommended