The film opens with a character referred to simply as the "Thief," who appears to be engaging in a sinister experiment involving a peculiar type of larva known for its unusual effects on the human psyche when consumed.
In a nightclub, Kris (played by Amy Seimetz) is suddenly tasered and abducted by the Thief. After forcing her to ingest the larva, she enters a trance-like state of heightened suggestibility that the Thief manipulates to achieve his aims. He distracts Kris with mundane tasks, such as making a paper chain where each link quotes from Walden, while he subtly controls her mind. This manipulation leads Kris to liquidate her home equity, disclose hidden rare coins, and drain her bank account. Through the use of hypnotic suggestion, she's restricted to only drinking small amounts of water at specific intervals, which are made to seem tantalizingly refreshing. Eventually released, Kris is left to gorge on food and sleeps in filthy clothes in her home, only to awaken and find a disturbing sight: large worms writhing beneath her skin. In a desperate attempt, she tries to cut them out with a kitchen knife but to no avail.
Later, a character known as the "Sampler"—a pig farmer and field recordist—draws Kris to his farm using infrasonics. In a silent operation, he transfers a worm from her body into a young pig via a bizarre transfusion. Kris then finds herself waking up in an abandoned SUV on the highway, her memory hazy and fragmented. On returning to her disheveled home, she notices suspicious blood on her sheets and floors but feels powerless to explain her situation to the police, ultimately abandoning the idea of calling for help. After cleaning up, she heads to work, only to get fired for her unexpected absence. A trip to the grocery store reveals the shocking truth: her personal finances are entirely depleted.
A year later, as she rides a train, Kris encounters Jeff (portrayed by Shane Carruth) and they develop a connection. Their bond deepens over several encounters which culminate in a night together. They soon discover an unsettling coincidence—they both bear identical surgical scars from those mysterious transfusions. Their conversation reveals that they’ve experienced similar traumas; Jeff lost his job due to embezzled funds taken from him, which he mistakenly associated with drug misuse. Meanwhile, the film hints at a significant parallel between Kris and Jeff's emotional states and two pigs, including the one hosting the larva from Kris: Kris erroneously believes she is expecting a child as her pig counterpart is indeed pregnant. A medical consultation reveals the shocking diagnosis of endometrial cancer that was successfully treated, yet it has rendered her infertile.
As the story unfolds, the Sampler's pig gives birth to piglets, which he discards by tossing them into a river—a haunting parallel to the intensifying feelings of loss and chaos that Kris and Jeff experience, leading them to act out irrationally. Kris recklessly searches for something lost while Jeff confronts his co-workers in a fit of rage. Their frantic feelings culminate in a reunion at Kris’s home, where they arm themselves with supplies, including a gun, taking refuge in her bathroom tub as they prepare for inevitable turmoil. Simultaneously, the discarded piglets rot away, releasing a blue substance into the water that fosters the growth of orchids, which capture the attention of farmers operating in the Thief’s vicinity.
As these events unfurl, a shift occurs in Kris and Jeff’s experiences—they begin to merge their personal histories. Jeff observes Kris reciting Walden while swimming, and during this surreal moment, they start to connect the dots of their shared trauma. The film reaches a dreamlike peak when Kris, Jeff, and the Sampler meet at a table in a stark white room, leading to a striking confession by Kris about her awareness of the Sampler. In a sudden turn of events, he succumbs to a heart attack, an image echoed by a scene on the pig farm where Kris shoots and fatally wounds him.
In the aftermath, Kris and Jeff gather records from others who have also suffered at the hands of similar mind control, inviting them to the farm by mailing out copies of Walden. The farm is transformed into a better haven for pigs, the senseless drowning ceases, and the blue orchids dissipate—finally cutting off the Thief’s access to the larva that fueled his trade. The film concludes on a peaceful note with Kris cradling a baby pig in her arms, a serene embodiment of hope and renewal.
