A family on a peaceful weekend getaway unknowingly enters a dangerous game of life and death and must work together to survive the night. One evening, a person wearing black gloves records The Pines Hotel's facade from outside. Meanwhile, inside the building, hotel owner Linda vacuums the hallway carpet, but she stops when she hears a noise.
When the device doesn't turn back on, the woman checks the outlet and sees the severed cord. Suddenly, Brad, the maintenance man appears, startling Linda. So, he explains that he stayed after hours to do last-minute checks before the big reopening this weekend.
The man sees the cord and thinks they might have a rat infestation. When the woman says she'll check the basement, Brad advises her against it and says he'll lay a few traps before calling it a night. After the maintenance man leaves, a person wearing a long black coat throws Linda into a glass table and drags her away.
Elsewhere, Roy Keenan solemnly watches old home videotapes of his kids when they were younger. Suddenly, the camera stops working, so he wipes away his tears and calls on his son, who doesn't answer. The father enters the bedroom, annoying his son Kevin, who says he's in the middle of a gaming livestream.
Roy apologizes, promises to respect the sign on the bedroom door next time, and asks the boy for help fixing the camera. In the living room, Kevin says he can't fix the outdated technology, but he might be able to digitize the tapes to save the footage. Seconds later, the doorbell rings, and the father sees his teen daughter Taylor with two police officers.
The cops explain that she was caught stealing alcohol from a store, and Roy's exasperated reaction implies that it isn't her first offense. Fortunately, the store owners won't press charges, but the police officers warn that she might not be so lucky next time. When she hears her husband and daughter arguing, Elaine appears and orders the teen to head to her bedroom.
In the kitchen, the couple expresses their disappointment at Taylor's rebellious attitude and remembers that she wasn't always this way. They acknowledge that they weren't the first parents to deal with a disobedient child and the family just needs to get through the tumultuous phase. So, Elaine suggests they go on a weekend getaway to The Pines Hotel and Roy agrees that it's a fantastic idea.
Meanwhile, in the hotel basement, a person wearing a plague doctor mask kills the tied-up Linda with a power drill. That weekend, the Keenan family arrives at the establishment, and upon entering, Taylor spots two men making their way to the bar. At the front desk, Mr Lockwood offers newlywed guests Mr and Mr.
Welsh the honeymoon suite. While the family waits for their turn, Taylor sneaks off to the bar where she overhears the French men she saw earlier talking about her favorite band, First to Eleven. She tells Theo and Louis that she has tickets to the concert but she can't go because her parents dragged her to the hotel for the weekend.
Then, Theo buys the teen a drink from the bartender Mark, much to her delight. Concurrently, Roy hands over his card, but Lockwood says their credit system is down due to the construction. Upon hearing this information, Kevin asks if that means the hotel doesn't have Wi-Fi either, which the man confirms.
He adds that their establishment is for spending time with the people you love because you never know how limited that time is, and the parents appreciate his words. At the bar, the irritated Louis rolls his eyes as he watches his friend and the teen flirtily take pictures on her phone. Suddenly, she receives a call from her mother but chooses to ignore it.
However, when it rings again, Taylor says she needs to go and promises to stop by their room later. As she's leaving, she runs into Elaine, who says she wants to have a drink. When Mark brings Taylor's unfinished glass of beer to the table and calls her Nicole, the mother realizes she used her fake ID again.
So, the woman says she doesn't want to stop her daughter from having fun and all she wants is for her to be careful. Meanwhile, in the back parking lot, a housekeeper walks to her car after her shift. In the distance, she spots a masked man placing a noose in a tree.
Suddenly, the man starts running toward her, but when the woman tries to open the vehicle, she realizes it's locked. Seconds later, the masked man's accomplice kicks the door from inside the car, causing the housekeeper to fall to the ground. As the tormentor approaches, the helpless woman screams in terror.
At the lobby, elderly janitor Oswald sees the unfamiliar Lockwood and asks where Linda is. The man explains that the owner hired him to help run the hotel, especially with all the recent changes. Concurrently, Roy and Kevin see Brad installing a wireless security camera to the ceiling, and when the boy asks how it'll work, the maintenance man says they have Wi-Fi, just not for the guests.
Suddenly, Howard, another guest, drunkenly knocks the ladder over, causing Brad to fall to the floor and destroy the device. In a side room, Lockwood knocks out Oswald with a fire extinguisher. Eventually, the Keenan family enters their room and Taylor complains about having to share a bed with her hyperactive brother.
When Roy sees Kevin using his tablet, he reminds his son that he can't play any video games this weekend. The teen annoyedly points out that her phone doesn't have service, so Elaine reminds the daughter about how she used to have so much fun at the resort, such as the one summer when Linda brought her to the roof so she could look at the stars. Then, the father reveals that they're going to the nearby amusement park Ultimate Universe tomorrow, much to his son's delight.
Meanwhile, Brad walks in on Lockwood and Bobby figuring out how to carry the janitor's unconscious body to the basement. When asked for help, the maintenance man says he doesn't get involved in the gruesome parts of the sinister operation. Then, Lockwood sees the camera in his hand, so Brad explains that it's malfunctioning but it's no big deal because he covered everywhere else.
After both Bobby and Brad fulfill their duties and leave the hotel, Lockwood locks down all the doors. In the arcade, Mark finishes fixing a machine and tests it out. Seconds later, he sees the masked Player 1 standing by the doorway and says the room's closed for the night.
After the mysterious stranger walks away, Player 4 suddenly appears behind the bartender and slams his head into the machine. Then, the attacker uses a cable cutter to remove Mark's nose, before bludgeoning him to death with a hammer. Concurrently, Taylor looks at the pictures on her phone, and after seeing her family sound asleep, she decides to sneak out.
Soon, she knocks on Room 207 and the French man lets her in. When the teen sees Louis lighting a spliff, she says it's a bad idea because most hotel rooms in the US have smoke detectors. Then, Taylor suggests heading to the roof and smoking there, so they leave the friend all alone in the room.
Minutes later, Elaine wakes up because of the music and noise from the adjacent room. So, the woman wakes her husband and asks him to tell their neighbors to keep it down. Roy knocks on the door and explains the situation, so the inebriated friends Sebastian, Sarah, and Michelle apologize for the inconvenience.
In the honeymoon suite, Mr and Mr. Welsh do the deed in the in-room hot tub. Suddenly, the terrified woman spots Player 3 by the bed and screams.
When her husband orders the intruder to get out, Player 2 hits his head with a champagne bottle and drowns him in the water. While the female killer restrains her, Mr. Welsh watches in horror as her spouse perishes.
Then, the woman manages to wriggle away from the attackers, but Player 2 stabs her ankle with the corkscrew. When the clothless victim tries to escape, the masked man drags her back into the room. After realizing that Taylor's gone, Roy and Kevin head out to look for her.
On the roof, Theo and the teen smoke a spliff and share a kiss. At the lobby, the father and son find that there's nobody at the front desk, and when they try to open the door, they realize that it's locked. Unbeknownst to the pair, Player 1 is standing several feet behind them.
Later, Elaine hears a knock on the door but sees nobody through the peephole. Suddenly, Player 1 pops up, startling the woman, and she threatens to call the front desk about the prank. Moments later, she hears the keycard beep and thinks Roy and Kevin returned, but all she sees is the open door.
Concurrently, the father and son speak to another guest, Amy, but she says she hasn't seen the teen. Overhearing the conversation, David says the French men are in the room next to his because he couldn't sleep from all the noise they were making. Even though the man hasn't seen Taylor, he deduces she's likely still in the building because all the exits are locked up.
In the room, Elaine continues reading her book, but Player 1 suddenly pops up from behind the chair and attacks her. So, the woman grabs a pen from the table and stabs the man's face, then tosses glasses to keep the intruder at bay. However, when Elaine tries to run away, Player 1 throws a knife into her back and uses barbed wire around her neck to end her life.
In the basement, Lockwood observes the carnage on a computer screen and updates the feed following the woman's death, revealing that all the kills are live-streamed to an online audience. On the roof, Taylor suggests they spontaneously drive to the concert venue right now before her family realizes she's gone, and Theo agrees. Meanwhile, Roy knocks on Room 207 but no one answers, so Kevin says maybe she returned to their room.
In the basement, Oswald finally wakes up and the ruthless Lockwood stabs him with a spiral knife, ending his life. Because he's preoccupied with the janitor, the man doesn't see Theo and Taylor sneaking out. Soon, Roy finds his lifeless wife in the room and sobs in anguish.
He tries to call the police, but it doesn't go through due to the lack of phone service. In the hallway, he hands his son the tablet and says they need to find Taylor. After seeing the man's distraught state, David reveals that he's a retired police officer.
So, Roy shows him Elaine's body and he suggests they go to his room. Later, the father wonders if his daughter's dead too, so David shares that he's in Philadelphia to attend his estranged daughter's wedding and tells the man that he needs to be strong for his children. The retired cop takes out his gun and says they need to find Taylor as soon as possible.
So, Roy tells Kevin to stay in the locked room while he and David head out. Meanwhile, in the car, the remorseful teen remembers how excited her parents were about the weekend and considers returning to the hotel. By the pool, the retired police officer mentions a similar case where the residents of an apartment building were locked in and slaughtered one by one for some type of competition.
Suddenly, Howard appears and goes on a drunken rant about the locked doors. Then, his wife Donna arrives to reprimand him for his embarrassing state. Seconds later, they hear Lockwood's voice on the PA system explaining that they all unknowingly signed up for a game.
Due to the noise, fellow guests John and Amy come out of their rooms. Then, the sadistic gamemaster turns all the lights off, and when they turn back on, the guests see Donna and Howard's mutilated bodies. While Player 1 drags Amy by her hair and Player 4 crushes John's head with his bare hands, Roy and David hide behind the pool bar.
In the room, Kevin hacks into Lockwood's system and watches Player 4 kill Louis by tipping a vending machine on his body. Eventually, the gamemaster traces the boy's device and threatens to harm him. Worried the man might arrive any second, the child runs out of the room.
Concurrently, Sebastian, Sarah, and Michelle spot Players 2 and 3 at the other end of the hallway but think it's just a couple in a unique role-playing scenario. Suddenly, the masked man winds a music box and places it on the floor. When the tormentors take out their blades, Michelle makes a run for it, but Player 3 stabs her.
While Player 2 restrains Sebastian, Sarah realizes she can't save either friend and runs away. Then, the cruel pair nails the man's hand to the door and plays a game of tic tac toe on his body. In the stairwell, Sarah runs into Kevin, and after seeing Player 1, they flee to the nearest hallway.
The woman knocks on the doors, but none of the guests hear their cries for help. While the frightened pair anxiously wait for the elevator, the door opens and Player 3 grabs Sarah. In the basement, Lockwood interacts with the viewers through the chat room and commends Players 2 and 3 for racking up style points, revealing that the killers are competing with each other.
Soon, Roy and David emerge from behind the pool bar and the former picks up the gun. Meanwhile, the female tormentor chases Sarah into a storage room and the latter uses a trolley to push off the attacker. However, Player 3 pins Sarah down on the cart, so the woman grabs a fork and stabs the killer's neck, ending her life.
While looking for a way out, she finds a small window, but the noise she makes alerts Player 2. The masked man grabs Sarah's leg as she tries to crawl through the opening, but she manages to kick him off. Relieved that she was able to escape, the woman lays on the ground with a satisfied smile.
Unfortunately, the person wearing the plague doctor mask appears and kills her with a shovel. Concurrently, Roy and David return to the latter's room, but Kevin's no longer there. As they head back to the hallway, Player 4 attacks, pushing the pair back into the room.
To save Roy, the retired cop hits the killer with an iron, but the unbothered man throws him against the wall. Moments later, David retrieves the gun his companion dropped earlier and shoots Player 4 dead. In the hotel kitchen, Kevin crouches behind the counters to hide from Player 1.
However, the masked man sees the boy's reflection on the fridge and catches him as he tries to crawl away. Just as he's about to end Kevin's life, he hears a security breach alert ordering all players to report to the disturbance. So, Player 1 lets the scared child go, much to his relief.
Meanwhile, Theo and Taylor return to the hallway from the roof, and he mentions how strange it was that the lobby doors were locked, revealing that they caused the security breach moments earlier. Suddenly, they find Sebastian and Michelle's bodies, but Player 2 appears and impales them both with a single spear. Concurrently, Player 1 attacks Roy, but when he asks his companion for help, the retired police officer says he's secured his win and he needs to find a way out.
Confused, the man doesn't know what he's talking about, so David implies that he's playing the game in a way that ensures he gets paid handsomely. Moments later, David heads to the basement to check his bet on the computer, and he's delighted to learn that all his predictions are looking good and could potentially earn him 31 million dollars. On the feed, he watches Roy struggling against Player 1, and he says the man should just give up and let him win his bet.
The father sees the wires on the ceiling and remembers the maintenance man failing to install a camera from that angle. So, he pushes the attacker into the blind spot to ensure that no one sees what's happening. Seconds later, Player 1 emerges, and the delighted David believes he won his bet.
Suddenly, the person wearing the plague doctor mask surfaces from under the bloody sheet and stabs the retired cop with the spiral knife. Then, the killer reveals his face, and David sees that it's Lockwood. He says the man manipulated the game and reminds him that bettors are never allowed to interfere with the process.
Lockwood adds that he's had his eye on the retired cop years ago when he handled the case in the apartment building, and he can't believe David thought he wouldn't recognize him when he checked in. When the gamemaster sees that Kevin's still alive, he mocks the injured man and says he wouldn't have won anyway, since he bet that Roy would be the last kill. After David's final defiant words.
Lockwood ends his life with the power drill. Then, he informs Players 1 and 2 that whoever kills the child will be awarded triple points. Meanwhile, Taylor regains consciousness since only the tip of the spear reached her body.
In the kitchen, Player 1 finds Kevin hiding in a compartment, and while the child thrashes, the man reveals that he's Roy pretending to be the killer. Suddenly, Player 2 arrives, so the father tells his son to play dead. To show that he got the boy first, Roy carries the limp Kevin in his arms.
However, the suspicious gamemaster rewinds the footage and informs Player 2 that Player 1 is an imposter. While the killer pins the father down on the counter, the son stabs him with a knife. Then, while Roy holds the masked man over the stove, the child turns it on, burning the tormentor alive.
Realizing he has to take matters into his own hands, Lockwood grabs an ax and heads to the lobby to confront the pair. The father calls the gamemaster a sick and twisted man, but he counters that what they're doing is no different than the gladiatorial battles from centuries ago. Fed up with Lockwood's words, Roy tackles and pummels him with his fists.
After the fight, the father embraces his son and says everything's going to be okay. Suddenly, Taylor stabs the man from behind, thinking he's Player 1. The shocked teen can't believe what she'd done, so the dying father assures her that it's alright and tells his children to always look out for each other.
Seconds later, the gamemaster rises to his feet and pins the teen against the wall. So, Taylor kicks him in the groin and uses the ax to chop his head off. In the morning, Detective Hart tells the siblings that he can't imagine what they went through and adds that their father was a hero.
Then, they see the authorities roll out the unmasked Player 2, revealing that he's still alive. After handing the pair some drinks, a medic checks his phone and smiles at his winnings. Days later, the new Lockwood informs the viewers that the next game will take place in a hospital.
All over the country, streamers of all ages and social classes eagerly await the start of the competition. Concurrently, another game is underway in a movie theater where Sofia watches in horror as a player butchers two people by the locked exit. The owner Bruce tries to open the door from outside, but another attacker places a plastic bag over his head.
Later, this iteration's wheelchair-bound Lockwood introduces himself to the woman who has a noose around her neck. Then, his lackey, Jimmy, presses a button, electrocuting the helpless Bruce.