A teenager’s weekend at a lake house with her father takes a turn for the worse when a group of convicts wreaks havoc on their lives.
A group of neo-nazis led by Dominick escapes from custody. They make their way to a house in the woods where he is looking for a key for his own white supremacist agenda. Teenaged Becky Hooper evades them as they take her father Jeff, his fiancé Kayla, and her son Ty hostage. Dominick kills Jeff, prompting Becky to get revenge. She gouges out Dominick’s eye with the key before he sends his goons on her.
Becky kills the first guy, Cole, by jamming a sharp-edged ruler into his throat. Next guy Hammond is done in by a boat motor. The group’s muscle, Apex, shows remorse over his involvement in everything and tries to let Becky get away safely while leaving Dominick behind. Becky then goes after Dominick, while Apex returns to try and help. Becky runs over Dominick’s head with a lawnmower while she doesn’t forgive Apex and shoots him in the head.
Becky is questioned for the killings but doesn’t say much. Kayla and Ty are also safe.
Pre-teen Becky Hooper is being questioned regarding an event that recently took place at her family’s house. She gives vague answers and does not seem to remember what they are discussing.
Two weeks earlier, Becky was a bullied high school student whose mother passed away a year ago. She has a strained relationship with her father Jeff, who attempts to reconnect with her with a trip to their lakefront home. Meanwhile, prisoner Dominick, a Neo-Nazi, and his men Apex, Cole and Hammond are riding in a transport van. Dominick has an inmate killed to get the guards to pull over, using the opportunity to kill them and pose as policemen. They stop a man and his two children on the street, kill them, and take their car.
Jeff’s girlfriend Kayla and her young son Ty arrive at the house, upsetting Becky. Jeff announces that he and Kayla are engaged. Hurt, Becky runs out of the house, followed by one of her dogs, Diego. At her small fort in the woods, she finds a mysterious key inside a tin box. Dominick and his men show up at the house, demanding the key and holding everyone hostage. Kayla and Ty try to escape but are caught by Apex, who tries to help them while Cole kills Dora, one of the family’s dogs. Jeff lies about Becky’s presence to protect her, but Dominick catches on and shoots Kayla in the leg to get the truth out of them.
Becky, still in the woods, becomes aware of the intruders’ presence and talks over a walkie-talkie, lying about calling the cops; Dominick calls her bluff and brings Jeff outside to lure Becky out. He begins to torture Jeff with a fire poker. Becky relents and says she will give him the key. Dominick allows Jeff to talk through the talkie, but he orders Becky to run. Jeff breaks free and finds Becky, telling her he loves her before being shot dead. Dominick demands the key and Becky gouges out his left eye with before fleeing with Diego.
Dominick goes back into the house to cut off the dangling eye and sends Cole and Hammond out to retrieve the key. Cole finds Becky and Diego in her fort. Before Cole can negotiate, Becky stabs him repeatedly with a sharp ruler and kills him.
Apex shows Kayla and Ty compassion and Dominick realizes Apex is going soft. He tries to have Apex reaffirm his loyalty to him since he has been planning this job for years while in prison. After finding Cole’s corpse, Hammond chases Becky down to the lake, where she makes him trip and land on a wooden plank of nails. Hammond falls in the lake and Becky uses a nearby boat to violently shred Hammond’s chest with its motor, killing him. She is found by Apex, who incapacitates Diego. Not wanting to hurt Becky after his guilt over killing the two children earlier, Apex urges her to flee.
Becky makes her presence known to Kayla and Ty; Kayla tries to distract Dominick by asking of the key’s purpose. Becky sets off the car alarm to lure Dominick out as Kayla tries to free herself. Apex fends off Dominick long enough for Becky to use a lawnmower to run over Dominick’s head, killing him. Apex thinks he will be redeemed for saving her but Becky shoots him in the head instead. Kayla and Ty come out with Diego and sit beside Becky as they wait for the police.
In the present, Becky denies murdering the Neo-Nazi gang, even though they know she did it. The sheriff expresses concern over the fact.
The film starts in an office where Becky Hooper (Lulu Wilson) is being asked questions regarding an event that recently took place at her family’s fort. She gives vague answers and doesn’t seem to remember what they are talking about.
Two weeks earlier, Becky is just a regular high school student. Her mother passed away a year ago, and she has a strained relationship with her father Jeff (Joel McHale). He goes to pick her up from school in the middle of the day, and she is none too pleased. As this happens, a neo-nazi prison gang, is engaging in a brawl, which ends when leader Dominick (Kevin James) gives one of his men a shiv to kill their rival.
Dominick, plus cohorts Apex (Robert Maillet), Cole (Ryan McDonald), and Hammond (James McDougall), are riding in a transport van. Dominick instructs Apex to kill the inmate next to him to get the guards to pull over. They use this opportunity to kill the guards and pose as policemen. They stop a man and his two children on the street, where Dominick kills the man, and Apex presumably kills the kids, and they take their car.
Becky is rude to Jeff on the way to the house because she thinks that he is selling the home when it meant something to her mom. He reveals that they are keeping it, but Becky is more upset when Jeff’s girlfriend Kayla (Amanda Brugel) and her son Ty (Isaiah Rockcliffe) arrive. Jeff sits them all down to announce to Becky that he and Kayla are engaged. Unsurprisingly, Becky takes the news poorly and runs out of the house, followed by one of the dogs, Dora. She goes to be alone and reminisce about her mom, but she also finds a mysterious key.
The neo-nazis soon show up at the house, initially appearing friendly until their true motives are quickly made clear. Kayla and Ty try to get away in the woods after Apex tries to let them sneak out, but they are cornered by Cole and Hammond. He is startled by Dora and shoots her. They take Kayla and Ty back into the house, with Kayla pretending that the dog was Becky after her name is mentioned, so as to also not scare Jeff. Dominick is there to look for the very same key that Becky just found. He shoots Kayla in the leg to prove he’s serious but deliberately misses the bone. Becky becomes aware of their presence, and Dominick knows Becky is a person who is near the area. She talks to him over a walkie-talkie she left there and tries to bluff by saying she called the cops from the neighbor’s house. Dominick knows she’s lying.
Dominick brings Jeff outside to lure Becky to him, since he knows she’s in the woods behind the house, and he starts to torture Jeff so Becky can watch. She relents and says she will give them the key. Dominick allows Jeff to talk through the radio, but he orders Becky to run. Jeff manages to break free from Apex’s grasp and kick Dominick in the face. He runs and manages to find Becky, but he only makes it long enough to tell her he loves her before Dominick shoots him dead. He catches up to Becky and demands the key, which she reveals by using it to gouge out his left eye, allowing her to run with the other dog, Diego.
Dominick goes back into the house to cut off the eye and sends Cole and Hammond to go after Becky while he and Apex keep an eye on Kayla and Ty. Cole manages to come across Becky and Diego as they are hiding in a small fort. Becky climbs to the top and ziplines her way down to attack Cole. Using a sharp-edged ruler, she stabs Cole repeatedly until she jams the ruler through his throat, leaving him a bloody mess.
Apex shows Kayla and Ty some compassion when they ask for help, but Dominick knows Apex is going soft. He tries to have him reaffirm his loyalty to him since he has been planning this job for years while in prison.
Hammond then tries to go after Becky next. After finding Cole’s corpse, he chases Becky down to the lake, where she makes him trip and land on a plank of wood with the nails sticking upwards. She hits him more with the nail end of the board until Hammond falls in the water. Becky then hops on the boat and moves it toward Hammond, using the motor to violently shred Hammond’s chest until he dies. As she tries to run, she is found by Apex, who knocks Diego down with a hard hit. He doesn’t want to hurt Becky after his guilt over killing the other two children, so he tries to let her go and get away from Dominick altogether. Diego also turns out to be okay.
It is now getting darker. Becky comes across Jeff’s body in the woods to apologetically and tearfully tell him she loves him and to say hi to her mom. She makes her presence known to Kayla and Ty, but Kayla tries to distract Dominick so he won’t see Becky. Kayla asks him what his whole plan was after mocking him for the futility of it all, to which he basically responds that it’s to fit his white supremacist agenda. After Kayla kicks him in the face, Becky sets off the car alarm to lure Dominick. A fight happens in which Apex returns to get Dominick, but he shoots him in the chest to fend him off. Becky then gets Dominick on the ground and uses a lawnmower to run over his head and turn it to paste. Apex apologizes for leaving Becky to face him, thinking he will be redeemed for saving her…but she shoots him in the head. Kayla and Ty then come out with Diego and sit beside Becky as they wait for the police.
We return to the office where Becky is talking to the sheriff and a psychologist. Becky never really owns up to the murders, even though they know she did it, and the sheriff expresses concern over the fact.