The film begins with Celeste, portrayed by Adria Arjona, an ex-army sniper, honing her shooting skills on some pumpkins outside her trailer. The tension in her arms is evident as she even uses her ring to inflict a small bruise on herself, which surprisingly assists her focus and steadies her aim. Meanwhile, Dr. Hans Kammler (played by Dan Stevens) and his wife Hanna (depicted by Rebecca Hall) seem to be starting their day with an unusual intimacy. Hans departs on a helicopter for his laboratory while Hanna watches from below, concerned.
In a poignant scene, Celeste’s ex, Griffin (portrayed by Jacob Scipio), brings their daughter Daisy (played by Blake Kennedy) to the trailer park. As Daisy enters the trailer, Griffin breaks the news to Celeste that he plans to relocate with Daisy to another state. Celeste reacts with distress, fiercely confronting him about his wish to separate her from their child. Among the residents at the trailer park are Josiah (played by Reginald VelJohnson) and Kovacks (portrayed by Eric Wareheim), who add to the mix of Celeste’s complicated life.
In a darker turn, Hans and his team conduct experimental tests on three male subjects who are ex-soldiers. They are being closely observed by Baylor (portrayed by Michael Biehn), who represents an unidentified organization. The first subject, known as Crybaby (played by Tyler Hall), earned his nickname for breaking down after a horrific event involving civilian casualties. The second, dubbed Cockroach (portrayed by Dave Campbell), has survived numerous gunshot wounds, while the last, The Butcher (played by Alex Pereira), was once a combat instructor notorious for his brutal methods. In a shocking display of their capabilities, Hans exposes the men to a lethal gas, leading to a horrific outcome where they ultimately rise against their handlers in a violent rebellion.
As chaos unfolds, Celeste takes Daisy to a gas station for refreshments. The tension escalates when Daisy glimpses the trio of brutalized soldiers, who vanish before Celeste can see them. Shortly after, the three men arrive, wreaking havoc at the gas station, leaving no survivors. This incident draws the attention of Cyrus (portrayed by Drew Starkey), an agent who is notified and begins tracing the path of destruction left behind by the super soldiers. At the tragic scene of Hans's lab, he learns the horrifying truth from Larkin (played by Leon M. Brown) that Hans has been manipulating these men to function as ideal combatants, stripped of their humanity.
Cyrus's mission intensifies when he is directed by Hanna to monitor the chaos rather than intervene directly. As the evening progresses, the super soldiers descend upon the trailer park, where they begin their slaughter. In a gut-wrenching moment, The Butcher murders a resident doing laundry, while Cockroach kills another neighbor during a casual barbecue. Amidst the chaos, Celeste realizes the danger and rushes to protect Daisy, but not before losing her eye during a brutal encounter when Crybaby attempts to invade her home.
As they flee for safety, Celeste musters her courage and arms herself for a fight. When Crybaby aggressively pursues her in a chainsaw duel, Celeste fights back heroically, ultimately leading to a violent conclusion where she avenges her injuries by slaying him. The turmoil continues as Cockroach meets his end in a deadly car crash, while Daisy narrowly escapes from The Butcher’s clutches.
In an emotional climax, Celeste confronts The Butcher, discovering his identity—he was part of her infantry once lost in battle. In a fierce encounter, she defeats him, impaling him with a chainsaw. After the horrific night comes to an end, government agents, including Cyrus, arrive to clean up the aftermath, while Josiah gradually regains consciousness from his wounds. Cyrus informs Celeste that for her and Daisy’s safety, they need to relocate and remain silent about the events that transpired. In the end, Hanna views the grotesque experiment as a twisted success, while Celeste reassures Daisy, hinting that change might be on the horizon for them both.
