Mary and Paul, striving to attend a funeral far from home, decide to leave their son Henry in the care of his grandfather, Jacob, on his secluded Canadian farm. The moment Mary arrives, she finds herself captivated by the barn—a haunting reminder of her mother's tragic end, which followed her discovery of Jacob's infidelity.
Once his parents depart, Henry engages in chores around the farm under Jacob's watchful eye, who also takes the time to teach him how to throw a baseball. However, the peaceful day takes a turn when Henry encounters Jacob's peculiar neighbor, Dixon. Just as Henry begins to warm up to Dixon, Jacob intervenes, displaying a protective instinct by reprimanding Dixon after an unexpected confrontation causes Jacob to strike him.
As night falls, Jacob and Henry stay indoors, while Dixon lurks outside, observing them with a sinister intent. The next morning brings harrowing news as Henry finds Jacob lifeless in his bed. In a panic, he attempts to leave a voicemail for his parents, but a raging storm disrupts the signal, leaving Henry desperate as his phone dies.
Mary and Paul receive a snippet of Henry's urgent message and take immediate action, leading to a welfare check by Sheriff Connie Munroe. But Mary, feeling a deep sense of unease, insists on returning to be with her son. Meanwhile, seeking solace and assistance, Henry turns to Dixon, revealing Jacob's body.
Dixon deceptively claims that the storm has rendered his landline useless, further isolating Henry from his parents. Sensing something amiss, Henry cleverly swaps their drinks, making Dixon consume the soda he had drugged. The atmosphere becomes increasingly menacing as Dixon expresses disdain for Henry's bond with Jacob, hinting at dark family secrets.
In a shocking twist, Henry discovers that the phone line is functional after all, confirming Dixon's lies. As tension escalates, Dixon lunges at Henry, only to succumb to the effects of the drugged soda.
Determined to protect himself, Henry improvises, crafting booby traps around the farm. Yet, influenced by a vision of Jacob, Dixon awakens with wrath, brandishing a baseball bat as he searches for Henry. The chase intensifies, leading to moments of harrowing confrontation marked by Henry's clever tactics, which include lighting Dixon on fire.
In a chilling revelation, Dixon admits to being Jacob's estranged son, a fact kept hidden from both families. He violently captures Henry, unleashing his fury. But just as the situation reaches its peak, Sheriff Connie arrives, only to become another victim of Dixon's rage.
While hiding in the barn, Henry discovers a woman trapped in a cage who implores him for help. As the confrontation escalates, a deadly standoff ensues, resulting in both Dixon and the caged woman sustaining grave injuries.
As Dixon lies dying, a vision of Jacob appears, revealing the heart-wrenching truth of his concealed lineage. Henry, contemplating revenge, ultimately refrains from striking Dixon's corpse with the bat. The nightmare nears its climax when Deputy Sheriff Drew finds Henry, leading to the arrival of Mary and Paul. In the midst of the chaos, Henry glimpses Jacob in a final vision as his parents guide him away from the tragedy that unfolded at the farm.
