The film opens with to young criminal lovers Mickey (Bill Skarsgard) and Jules (Maika Monroe) robbing a gas station. Mickey can't get the register open since he caused the cashier to faint. Jules hands him a snack to buy so they can open the register and make off with the money...and the snack.The two are heading to Florida to get away from the police and their worthless lives. Jules gets excited and tries to have fun with Mickey on the road, but their car quickly runs out of gas, and the irony of having just robbed a gas station hits them. They decide to walk until they can find another solution to keep moving. They leave the car stranded until they come across a nice house. They start to break in until Mickey sees that the front door is dead-bolted shut. Jules hands him a crowbar and they break in.Mickey and Jules start to make themselves comfortable as they try to figure out their next move. They snort cocaine, which gives Mickey the idea to siphon gas from the homeowners' car and carry it with them to their car. They run to the basement to look for a hose, but they end up discovering a little girl (Blake Baumgartner) chained to the floor. Jules wants to help her, but Mickey thinks it's a bad idea. He relents and decides to help get the girl out.The two run back up to the kitchen and are found by the homeowners, a seemingly friendly couple named George (Jeffrey Donovan) and Gloria (Kyra Sedgwick). Mickey aims his gun at them, but George calmly attempts to diffuse the situation once he realizes they are trying to break the girl (whom the couple calls "Sweetiepie") out. George suggests that Mickey and Jules take what they want and get out of there so that the police aren't involved, but Mickey makes it clear they are not leaving without the girl. The couple relents and brings the crooks back down to the basement. George unchains Sweetiepie, but when Mickey tries to take her with him, she bites his wrist, and George headbutts Mickey to knock him out.Mickey wakes up tied to a bed. Gloria attempts to seduce him, though she creeps him out by playing up a mommy fetish. She also shows him pictures of her supposed son that she calls "Ethan." Meanwhile, Jules is stuck in the basement tied to the support beam. She tried talking to Sweetiepie, but she remains unresponsive. This goes on for about two days. Jules admits to the girl that her parents abandoned her when she was a child. Mickey appears to give into Gloria's seduction, but when he asks to touch her, she uncuffs him and gives him an opportunity to throw her off of him. Mickey makes a run for the door but is stopped by George with his gun. He forces Mickey to go to the basement and stay tied up with Jules.Mickey and Jules plan their escape. He remembers her tongue stud and tried to convince her to take it out so that he can use it to pick the locks. Jules is hesitant since she knows it will hurt, but with Mickey's help, they are able to pull it out. He manages to uncuff Jules, but when she tries to get his cuffs, the stud breaks inside. Thinking quickly, Jules runs for it to try and find another way to help Mickey. George comes down and sees that Jules is gone, and he threatens to cut Mickey's ear off to get him to talk. He quickly says that Jules went somewhere to meet Mickey, and if he isn't there at a certain time, the cops will come. George believes him and uncuffs him to take him outside.As they head for the front door with Mickey at gunpoint, Jules emerges with "Ethan", who is just a porcelain doll that Gloria has a deep attachment to. Jules threatens to drop Ethan unless George lets Mickey go. Gloria instead grabs George's gun and shoots at Jules, but she missed and causes her to drop Ethan, and his head shatters. Gloria tearfully tries to piece the doll back together. George keeps Mickey and Jules hostage.George and Gloria strap Mickey and Jules to chairs as they are seated for dinner, with Gloria preparing a shepherd's pie. Mickey and Jules eat the food and ask what the whole deal with Sweetiepie is. George explains that she was kidnapped by them since Gloria is barren and couldn't have have kids. However, she couldn't see Sweetiepie as her own child, so she ordered George to get rid of her. He views her being captive in the basement as a form of mercy. Mickey and Jules then start to feel dizzy, and George reveals that they were just fed an excess amount of pills to knock them out before George plans to overdose them with heroin and make it look like they are just two junkies who broke in and went on a bender before dying.The plan is interrupted when a cop comes to the door, as Mickey and Jules's car was found abandoned near the scene of the gas station robbery. George assures the cop that everything is fine, but he becomes suspicious when he sees the broken door. George reluctantly lets the cop inside. Gloria has stashed Mickey and Jules away in their gym to keep them hidden from the cops. The officer then goes down to the basement. George prepares to shoot him before he discovers Sweetiepie, but he is called back outside by the other officers.Jules manages to wake up and get cocaine for herself and Mickey to get them back on their feet. They trick George and Gloria into thinking they ran away, and they emerge after the older couple heads out to find them. While walking in the woods, Gloria says she has had enough of George insulting her out of frustrations, and she admits she would rather forget about Mickey and Jules and just carry on with their lives by going on a trip. Meanwhile, Mickey and Jules prepare to take George and Gloria's car, but they end up agreeing to free Sweetiepie. She only goes after Mickey apologizes for yelling at her after she bit him.The young couple makes it to the garage but can't find the garage door remote. George and Gloria have returned home to find that their keys are gone, and so is Sweetiepie. George heads the garage door opening, and he makes it to the front before Mickey and Jules can get away. He holds his gun at them and orders them to step out of the car. Mickey tells Jules he loves her right before he hits the gas and runs George over. Unfortunately, Mickey has been shot in the chest. He has a brief final moment with Jules before he dies. Jules cries over Mickey's body before a now horribly disfigured George pulls her out and tries to strangle her. He is stopped when Sweetiepie steps out the car and grabs his gun. He tried to sweet-talk her into giving him the gun, but she instead shoots him in the head. Gloria comes outside with luggage for a trip before she sees George's corpse. She is now fully delusional and tries to "wake" George, and Jules cannot being herself to kill Gloria. Sweetiepie finally talks and says she will go with Jules. The girls walk until they are picked up by a kind woman, and she takes them to Florida.The last scene is a home movie style video of Jules and Sweetiepie (now actually looking like a cheerful child) enjoying a day at the beach in Florida, with them also having a small knick-knacks shop named after Mickey.