Stepphy, Jane Levy, a teenager living in the small town of Lonely Arms, dreams of becoming a famous singer. Her alcoholic father, Peter Stormare George, refuses to let her enter a singing competition in New York City. When a local man sexually assaults her, Stepphy is left grappling with trauma and begins to experience dissociative delusions that coax her toward a fantasy: that her fate might shift if her idol, Bobby Shore, Justin Chatwin, shows up in town after his car breaks down.
Meanwhile, a dangerous leak at the town’s chemical plant starts turning residents into mutants, triggering a quarantine thatlocks Lonely Arms from the outside world. As the town teeters on the edge, Stepphy’s mind wanders between the harsh reality around her and a haunting alternate vision in which everything could be different.
Her delusions deepen when she becomes pregnant with her assailant’s child, and she convinces herself that she is marrying her idol Bobby. The fantasy intensifies with every memory of the assault, looping back on itself as she tries to navigate a life that feels both out of reach and dangerously close to truth. The wedding night arrives, but a brutal flashback erupts. In the heat of the moment, Stepphy strikes Bobby, who flees, and the illusion of their perfect union collapses, leaving her to confront a terrifying new reality: she is now married to the man who attacked her, and she is pregnant.
Labor brings a startling new reality into the world: a mutated baby that can speak from birth. The government begins patrolling the town, distributing bottles of poisonous liquid to urge people to end their own lives rather than live with the mutations caused by the purple mist from the factory accident. In a moment of crisis, Stepphy wakes to the baby’s call and contemplates taking the poison herself. The infant’s garbled, earnest plea—“mommy, don’t leave me alone”—shatters the last threads of her delusions and reframes the child as a normal crying infant rather than a miracle in disguise.
Her husband intercepts, attempting to seize the baby and force-feed the poison. Stepphy defends her child, striking him with a lamp and leaving him bleeding. With the danger temporarily behind her, she decides to flee. She heads out with her daughter, and her reluctant father refuses to come along, telling her that she and the baby should go and start anew somewhere else.
Stepphy and her daughter relocate to New York, where the dream of a music career finally seems within reach. A few years pass, and we glimpse her again as she auditions before a talent agent in the city, the moment framed as a hopeful beginning. The film closes on a quiet, hopeful note as she arrives to pick up her now five-year-old daughter from a park, ready to continue their life together in the big city.
