Seven days earlier, 17-year-old Reese Crane sits in the family car as they drive through rural Wisconsin toward the resort. Her father, Nolan, has gotten them lost multiple times, and her mother, Emily, won’t stop criticizing him. After an aggressive truck driver harasses them, Nolan jerks the car over and sarcastically offers to let Emily drive.

Reese tells them both to act like adults, which only angers Emily further. Frustrated about being stuck on this trip, Reese texts her friend, Skylar, sarcastically that she feels like attempting suicide. She reflects on her family: her 14-year-old brother, Wyatt, secretly looks at porn but gets away with everything because he excels in school and baseball. Emily previously called Reese a “slut” because of her clothing.

When Emily insists Reese wear her seat belt, she complies angrily. Reese starts typing a retraction to Skylar, saying she wants to kill someone else instead, but the text fails to send due to poor cell service, and she deletes the unsent message.

Courtney spins around to find Cass and Mae standing in the great room. Relieved they are not an intruder, she rushes to them but notices drops of blood on the floor she previously missed. She snaps at them for disobeying her instruction to wait outside, her fear manifesting as anger. Cass begins to explain that she tried to stop Mae from following.

Courtney realizes Mae must have already discovered Emily’s body—the blood on Mae’s hands belongs to Emily. She tells the girls Emily is hurt, and they need to leave for help. When Cass points out Courtney has her phone, Courtney lies about having no signal.

As she turns the girls toward the door, Cass walks backward and suddenly releases a bloodcurdling scream at something behind Courtney. Courtney turns back to see what horrified her daughter.

The family arrives at the resort with Nolan and Emily giving each other the silent treatment. Earlier, Nolan told Emily the trip would be more enjoyable if she had stayed home.

Reese surveys the run-down property with disgust, noting the dated playground equipment and no beach. The resort was suggested by Reese’s Uncle Elliott, who had visited before. Their cottage is the largest but still disappointing. The interior is dark and musty with mismatched furniture and dead flies in the windowsills. Wyatt wants to drop his luggage inside the door, but Emily insists they carry everything upstairs immediately, sparking another argument with Nolan.

Courtney discovers Nolan’s lifeless body at the top of the stairs, blood seeping from his mouth and temple. As Cass continues screaming, Mae whimpers and wets herself.

Courtney covers Mae’s eyes and forces both girls out the front door, telling them Nolan is hurt and they must get help. They run down the hill toward their own cottage. Mae falls, and Courtney sends Cass ahead while helping Mae up.

Racing through the trees, Courtney feels overwhelming guilt about leaving Reese and Wyatt behind in the cottage. She glances back one final time and imagines seeing a pale face watching from an upstairs window.

Upstairs, Emily assigns bedrooms, telling Reese she must share a bed with 10-year-old Mae. Reese refuses and claims the screened-in porch with its single bed for herself. Emily forbids this for safety reasons, but Nolan overrides her decision, deepening Emily’s anger.

On the porch, Reese checks her phone. She discovers there is no Wi-Fi in the cottages and cellular service is unreliable. On Instagram, she sees her best friend Skylar has posted photos with another girl, Gracie, at Oak Street Beach—activities Reese and Skylar had planned to do together. Feeling jealous and replaced, Reese angrily throws her phone, accidentally breaking a glass lantern.

Through the screens, she spots a handsome boy her age walking alone in the woods. She becomes instantly infatuated. Emily enters with Reese’s bags and notices the broken glass, then asks if someone is outside. Reese lies, claiming she saw no one, though the boy remains hidden in the trees, watching them.

Courtney gets the girls inside her cottage and locks the door. Accepting that Emily and Nolan have been murdered, she tries her phone but has no signal. When she decides to go to the lodge alone for help, Cass desperately begs her not to leave. Courtney agrees they will all go together.

They run to the lodge, where they encounter the resident German shepherd that frightens Cass. Inside the dim lodge, Courtney sees a man at the bar and recalls seeing him make Reese uncomfortable by the pool earlier. The manager, Greta Dahl, emerges from an office looking for a late employee.

Courtney tells Greta that her brother and sister-in-law are dead in cottage eight. Upon hearing this, Cass realizes the full truth and cries harder. Greta looks outside to see if they were followed, then locks the door and goes to her office to call the police.

Courtney uses the lodge Wi-Fi to text her husband, Elliott, who left early that morning to go fishing. Greta returns saying police are on the way and gives the girls water and snacks. Mae becomes sick and vomits. The man from the bar leaves to check on his family, insisting on going despite Greta’s warning that it is not safe.

While waiting, Courtney notices Greta wiping the bar while staring at them with a cold, fixed gaze. Paranoia sets in, and Courtney wonders if Greta actually called the police at all.

Emily insists Reese take Wyatt and Mae with her on a walk. They head to the lodge so Wyatt can play arcade games. Outside, a man smoking a cigarette stares at Reese and then at Mae in a way that unsettles her.

Inside the lodge, Wyatt plays games while Mae browses DVDs. Reese notices a missing person poster for Kylie Matthews, a girl who disappeared five years earlier while riding her bike home. Through a window, Reese spots the boy from the woods unloading boxes from a truck. She becomes completely fixated on watching him, losing track of everything else, including Mae.

Someone pounds on the locked lodge door, terrifying everyone. Greta checks and announces it is the police. Several officers enter, and behind them stands Courtney’s 14-year-old nephew, Wyatt. Courtney embraces him with relief. He appears dazed but unharmed.

The lead investigator, Detective Evans, a young redhead, introduces himself. He confirms, to Courtney’s disbelief, that Wyatt was found asleep in his upstairs bedroom and glimpsed the bodies only briefly. When Courtney asks about her niece, Reese, Evans reports she was not in the cottage—only the two deceased victims and Wyatt were found. Courtney insists they must have missed her, but Evans is certain. She fears Reese has been abducted or killed elsewhere.

Evans asks how Reese got along with her parents, implying she might be a suspect. Courtney vehemently denies this possibility but remembers Reese’s fight with Emily the previous night, when Reese had shouted that she hated Emily and wished she were dead.

Courtney recounts that she and Elliott played cards at Nolan and Emily’s cottage until just after eight o’clock the previous evening. Evans asks where Courtney’s husband is.

From the lodge window, Reese watches the boy unload boxes and drink a Pepsi. He catches her staring, smiles, and waves. Embarrassed, she retreats from the window and decides to leave.

She realizes Mae has wandered off. After a frantic search, Mae emerges from behind a curtain marked for adults only, guided by a man. Reese snatches Mae away and scolds her for disappearing. On the way out, Reese points to the missing girl poster and warns Mae that a similar fate could befall her if she is not careful.

Walking back to the cottage, Wyatt threatens to tell their parents Reese lost Mae unless she pays him. They arrive to find Courtney, Uncle Elliott, and Cass visiting. The adults have been drinking. When Wyatt publicly asks if Reese wants to tell Emily what happened or if he should, Reese deflects by mentioning Emily owes her a dollar for the rented movie. While Emily retrieves her wallet, Reese secretly pays Wyatt hush money via Venmo.