The sun-drenched landscapes of Italy set the stage for the Dalton family – Ben (Scoot McNairy), Louise (Mackenzie Davis), and their 11-year-old daughter Agnes (Alix West Lefler) – as they seek solace in a picturesque resort. With Agnes clutching her beloved stuffed rabbit, Hoppy, a token of her need for comfort, Ben and Louise struggle to forge connections with the other guests, finding themselves ensnared in bland dialogues with a Danish couple. As fate would have it, calamity descends when Agnes misplaces Hoppy, spiraling into a frantic panic. Luckily, assistance arrives in the form of the empathetic British couple, Paddy (James McAvoy), Ciara (Aisling Franciosi), and their mute son Ant (Dan Hough), who promptly recover the cherished toy.
The Daltons, charmed by the warm-hearted Felts, indulge in a leisurely lunch, where Ben confides in Paddy about his recent move to London for work and the sacrifices Louise made. Paddy extends an invitation for them to visit his expansive country estate, planting the seeds of what might blossom into a deep friendship.
However, back in London, Ben grapples with disappointment over a missed career opportunity and worries about Agnes's attachment to Hoppy. When a postcard from the Felts reaffirms their invitation, Louise feels apprehensive about spending time with strangers, yet both parents ultimately decide to accept the offer.
Upon arriving at the Felts' estate just as dinner is being served, they are met with Paddy's pride as he presents a roasted goose. Despite Louise's vegetarianism, she tastes it but discreetly disposes of it when the adults aren’t looking. While Ben takes out the trash, Ant follows closely, trying to share his struggles with being mute. As the adults engage in conversation, both children end up in the same room, but the nighttime wails from Ant disturb Louise, though Paddy and Ciara reassure her that he will eventually settle down.
The next morning, a woodland hike ensues, where Agnes eagerly seeks to play. In a moment of discomfort, Paddy awkwardly moves Ant aside for Agnes to use the swing set. He suggests a refreshing dip in the lake to help alleviate Louise's neck pain, and as they make plans for dinner at a local eatery, Muhjid (Motaz Malhees), Ant's babysitter, will oversee the children.
At the restaurant, Paddy and Ciara's candid discussions about their vibrant sex life stir discomfort in Ben, particularly when Louise admits their intimacy has dwindled. Paddy and Ciara further tease them, mimicking sexual acts under the table, which raises the temperature of the moment. Meanwhile, Ant tries to share a collection of watches with Agnes, revealing the darker aspects of his life through his bruised torso, highlighting the pain he endures.
As the evening progresses, tension simmers between the adults. Ben expresses frustration over Louise's openness, stemming from his jealousy of another man's presence on her phone. Though they share a hug, unbeknownst to them, Paddy is watching their every interaction with intent.
Later that night, Louise awakens to find both children missing. After a panicked search, she discovers Agnes nestled next to Ciara, which eases her mind temporarily.
When dawn breaks, Louise's mounting frustration leads her to insist that they must leave immediately, wanting to escape the palpable tension. As the Daltons attempt a stealthy exit while the Felts sleep, their plans are thwarted when Agnes realizes that Hoppy is missing once again. In a desperate attempt to soothe her, Ben finds himself almost crashing the car. Defeated, he turns back to retrieve the precious doll, and as they confront Paddy and Ciara, Louise cannot hide her discomfort anymore. Ciara, to Louise's surprise, reveals her own motherly instincts, stemming from the tragic loss of their daughter Mary, prompting Louise to discover a shared vulnerability.
In a strange twist of fate, Paddy invites Ben on a traditional fox hunt while the women bond over their children. However, the atmosphere returns to discomfort when Louise feels targeted by Ciara's remarks at lunch. During a moment of innocence, Agnes and Ant showcase a dance, only for Paddy to harshly criticize Ant, casting a shadow over their joyous effort.
While a seemingly ordinary day unfurls, Ant secretly guides Agnes to a hidden basement in the barn revealing a chilling narrative—a collection of photographs documenting past families who crossed paths with the Felts, with each subsequent family signature of their children suggesting that they were victims of a sinister plot. In a moment of bravery, Agnes captures this horrifying evidence with her phone to show Louise.
Upon waking, Paddy catches on to the children’s secretive behavior, igniting a chain of desperate attempts to escape. As they concoct a pretext about Agnes's menstrual cycle, fate deals a cruel hand with a flat tire. As Paddy attempts to fix it, Ben retrieves Hoppy only to find it mutilated and shredded, while the family finds themselves ensnared in a perilous situation.
In a climactic twist, the Daltons, facing their dire circumstance, become ensnared and threatened at gunpoint, ultimately leading to a struggle for survival. In a moment of fierce defiance, Louise manages to grab a hidden weapon, escalating the dangerous confrontation. As chaos erupts, the family fights desperately, barricading themselves while searching for any opportunity to escape their nightmarish predicament.
In a brilliantly orchestrated showdown, Louise uses her surroundings as weapons, and together with Ben, they face off against their captors while battling to protect their children. The unfolding events culminate in a tense climax, where each decision weighs heavily and the lines between predator and prey blur amidst confusion and terror.
Amidst the violent struggle, they find a glimmer of hope as Ben attempts to signal for help via fire, yet each moment feels like it could bring them closer to their end. Just as they think escape is within reach, they encounter unforeseen barriers, forcing them back into the depths of fear.
They gather together, hearts heavy with the impact of their ordeal, as bonds are tested and alliances must form anew. As they navigate this tension-laden scenario, courage shines in Agnes and Ant, who, despite their ages, plunge into action against their ruthless captors. Their fight not only marks a significant moment of shared bravery but serves as a testament to the resilience of the human spirit in the face of dire danger.
In the end, as they flee, their harrowing escape threads through themes of sacrifice, survival, and the haunting shadows of their experiences. The last remnants of innocence linger as Agnes offers Hoppy to Ant, symbolizing their shared pain and the hope they carry away from a once-tranquil resort now marred by trauma.
