Note: This is a remake of the 2010 Uruguayan film La Casa Muda. Both the original and this remake were (allegedly) shot in one take with no cuts, similar to the film Rope by Alfred Hitchcock.
We begin with an overhead shot of a young woman, Sarah (Elizabeth Olsen) sitting on some rocks in a lake. As she gets off and begins to hop amongst the rocks back to the shore, the camera descends and begins following Sarah in real-time. She walks up to an obviously dilapidated house. The house is three stories tall. Sarah's father John (Adam Trese) meets her near the front steps and tells her sternly to pick up the gardening tools lying about. John then asks Sarah about her Facebook profile, and she admits that her ex-boyfriend may want to get back together with her, much to John's disapproval.
Her Uncle Peter (Eric Sheffer Stevens) walks through the front door and greets the two of them. He says that there is a big problem in the house. They walk in, and though it is daylight outside, the house is almost pitch black as all the windows are boarded. The trio turn on their electric lanterns and Peter stares at Sarah, telling her how beautiful of a woman she has become and begins tickling her. They follow Peter to the dining room (the source of the problem) where John hits the wall with a sledgehammer to reveal that mold has grown within the walls, and maybe throughout the entire house. Tools and clutter are strewn everywhere. They take a picture of the mold with their polaroid camera. John and Peter begin arguing over the state of the house as they are clearly trying to repair it for sale, and they debate whether to just patch up the hole and ignore the mold. John and Peter's relationship appears strained.
The three return to the foyer, and Peter says he is going to go into town. On his way out, Peter gives a long hug to Sarah, and John reminds him to call the electrician to get the power restored. John then goes b into the basement while Sarah locks up (and places the key to the front door on a hook next to it). Soon after, Sarah hears a knock on the door and sees a girl roughly her age standing on the porch. The girl gives a loving hug to Sarah and introduces herself as Sophia (Julia Taylor Ross), a childhood friend who lives in the town. Sarah says she honestly doesn't remember Sophia since it has been so many years since she has been to this house, and Sarah also jokingly states that she has holes in her memory. None of this deters Sophia from eagerly recounting the times they played together as kids. Sarah tells Sophia that she did not go to college and works with her dad restoring houses until she figures out what to do. Sophia asks Sarah why all of the windows are boarded shut with plywood, and Sarah explains that after the house was abandoned, drunk squatters lived there and broke every single window until the police forcibly evicted them. Sophia said that she tried to call, but the home phones are disconnected and Sarah does not have cell phone service so far outside of town. Sophia says she is glad she finally got to see Sarah again, and they make plans to meet up later that night to go out and continue to reminisce. As Sophia gets on her bike to leave, Sarah calls out that she does remember her. Sarah then returns indoors, once again locking the front door and returning the key to its hook, shutting out the daylight.
Sarah then lights two gas lamps and opens a beer. As she begins to take her first sips, she hears loud thumping noises coming from upstairs. She immediately calls her dad, who says it is probably just rats, but Sarah insists that they check it out. The two go upstairs to the second level to investigate, and as a "joke," her dad slams open a door hard into Sarah's arm. They walk into the master bedroom, and some polaroids are lying out on the bed that John quickly picks up (before Sarah can see them) and stuffs them in a night table, saying that they are pictures of the repairs and saying that Peter never learns how to put things away. John then takes Sarah to the room she used to stay in when they used the house when she was a kid, and insists that she clean the entire thing out and trash whatever she doesn't want. Sarah is relatively calm in her electric lamplight and can hear her dad walking around taking care of things in other rooms. She looks through her clothing, which includes a ballerina outfit, and begins stuffing things in a trash bag. She comes across a locked trinket box and throws it away.
At that time she hears a loud banging on the wall outside her bedroom. She calls out to her dad, but he does not answer. Sarah immediately panics and runs downstairs towards the front door, but the key is no longer on the hook. She then runs towards the kitchen door that leads outside, but finds it padlocked. She begins opening drawers to find the key, and in the background, a large, male intruder stands ominously watching her. She can't find the key, and the intruder is no longer there when she looks in his direction. As she continues to pace around, she hears footsteps approaching and hides under the dining room table, accidentally knocking down her beer bottle. A male hand leans down to pick it up, and Sarah can just barely contain her screams. The figure walks out of the room and Sarah begins hyperventilating, until she notices the intruder's hand trying to grab her leg. She manages to squirm out of his grasp and runs upstairs to a room and locks the door, pushing a dresser in front of it to barricade herself in.
After a few moments of screaming, Sarah calms down, and apparently, was not followed by the intruder. She begins trying to open the windows, but can't knock out any of the boards. As she searches the room for anything that can help her, a figure falls out from behind some drapes. Sarah screams loudly, but then realizes that the figure was her dad, who lies unconscious on the floor. She goes over to her dad and finds a huge gash on the side of his head. As she cradles him, she gets blood smeared over her shirt. John begins groaning, and Sarah is happy to find that he is still alive, though in bad shape. She knows that she has to get him some help, so she searches his pocket and finds a key. She listens to the door for awhile and hears nothing. She grabs her electric lantern, then pushes aside the dresser and exits the room to head for the exit.
She sneaks downstairs and tries to open the padlock on the kitchen door, but it does not work. Sarah panics once again and tries to knock of the lock, but soon gets ahold of herself again. Sarah soon comes to the sad realization that the key must belong to an exit located in the basement. She opens the basement door, and slowly descends the steps to the pitch-black basement. The basement is in total disarray, with tons of exposed pipes and machinery. It is clear that Sarah is unfamiliar with the basement layout as she keeps running into things. She opens a door to reveal what looks like a child's room that was recently used (the bed was unmade). At that moment, she hears loud, pounding footsteps descending the basement stairs. She hides behind the door to the room as the menacing intruder walks by, holding his own lantern. The intruder's search is unsuccessful though, and he soon is heard walking back upstairs. No longer able to keep her composure, Sarah runs throughout the basement, eventually opening a door to a storm-cellar with a padlock on the door leading outdoors. As she fumbles with the padlock, the footsteps hurry back downstairs, coming closer and closer. Sarah manages to finally unlock the storm cellar doors and flees outside.
Sarah runs in blind panic through a field and eventually hits the road. Finally having gotten a decent distance from the house, she stops in the middle of the road to catch her breath. As she turns around to look behind her, she sees a spectral young girl staring at her from the bushes. She screams, and as she does, a truck almost hits her. It is her Uncle John, returning from town. She leaps into his truck and he says he did not see any girl and demands to know what happens after he notices the blood on her shirt. She explains that an invader has infiltrated the house, and Peter insists that they go back to the house to get John, as the ambulance/police are a half-hour away. Despite Sarah's protests, they begin driving back to the house.
They arrive, and Peter pulls out his gun from the trunk and locks Sarah into the car as he goes inside to retrieve John. Sarah sits there, waiting for Peter to return. She looks in the rear view mirror and sees the intruder standing behind the car, but when she turns around, nobody is there. Sarah begins crying once again and returns her gaze to the mirror where she sees the trunk opening and the intruder crawling in through the back. She flees the car and runs into the house, and slams and locks the door (with Peter's key) behind her. Peter immediately runs to her and says it is impossible for anyone to have opened the trunk as he has the car keys in his pocket. Nonetheless, she insists that they stay together, and after Peter calms her down, he asks her to show him where she left John.
They go back up to the second level and into the room where Sarah left John. Unfortunately, John is no longer there, all that remains is a pool of blood. Peter is clearly upset and they begin searching around. Peter opens a closet and finds more polaroids, but like John before him, he quickly grabs them and throws them into a trash bag. Peter had apparently searched the basement before Sarah ran inside, so the only place left is the third level attic-type area. They go upstairs where a pool table is stored and a generator behind a tarp provides light. Neither of them knows who turned on the generator. The polaroid camera is sitting on the pool table. They sneak up to the tarp and rip it open, but nothing is behind it except for the generator. Suddenly, the generator goes out, and since Peter had turned off the flashlight when they went upstairs, the two are plunged into darkness. A loud thump is heard. Sarah manages to grab the Polaroid and begins snapping pictures to light the room with its flash. She sees her Uncle on the floor, the intruder lurking, and the girl standing and watching in successive flashes.
Sarah hides under the pool table, and eventually the generator springs back to life. Suddenly, Sarah begins having a hallucination. She sees a girl's legs clothed in a tutu and stocking hanging over the railing of the pool table (the girl is sitting on the pool table). There are two pairs of men's legs walking around the girl on the table (neither legs belonging to the intruder). They are taking pictures of the unidentified girl sitting on the table and saying things like "see, that wasn't too bad" and "it was a fun game." Suddenly Sarah is snapped back to reality and sees her Uncle Peter being dragged out of the room.
Sarah slowly follows Peter's dragging body down to the second level. The intruder is waiting for her on the landing and she runs into the master bedroom and hides under the bed. She hears another breath and looks behind her, to find the spectral girl also hiding under the bed, until the girl is violently dragged out from underneath. Sarah flees from the bedroom into the bathroom and locks it. She hears noises from the bathtub and pulls open the shower curtain to find the spectral girl, in a ballerina outfit, sitting in a tub of water and empty beer bottles. The girl begins pouring water out of the beer bottles onto herself, and the water soon turns to blood.
Sarah can't take any more of this and runs in full panic down the stairs towards the front door, where she sees Sophia in the foyer. She tells Sophia she can't get out. Sophia gives Sarah a key, but it doesn't work on the front door, with Sophia commenting that the front door is not the way out. Sarah follows Sophia into the dining room, where John lies gagged and bound to a chair. Sophia says that Sarah needs to remember what happens and plug up the holes in her memory. Sarah looks into a nearby mirror, and sees that her reflection is of the girl in the ballerina outfit.
Sophia hands Sarah the locked trinket box and Sarah opens it to find various polaroids inside of herself as the young girl on the pool table (the hallucination was actually a repressed memory). Sarah starts to realize that she had repressed memories of a traumatic event that had occurred in this house. The intruder enters the room, dragging a seemingly dead Peter who is bleeding from a stomach wound, but as the intruder passes Sarah, it morphs into her. Sophia explains that Sarah had done all this to her uncle and dad and tells her to finish the job, handing Sarah a knife. Sarah lashes out at Sophia instead, slashing Sophia on the hand. Sophia responds angrily, telling Sarah to stop hurting herself. Sarah looks at her hand to notice it is slashed in the same place she slashed Sophia's hand, and when she looks up, Sophia is no longer there, nor is the young girl or the intruder.
She begins flipping through the polaroids before flinging them at her dad who is now fully conscious. The pictures show blurry images of Sarah as a young child in various compromising positions, some in the pool room and others in the basement room. Sarah straddles her dad and asks him if he would like to play with her now, or does she need to be more quiet so she doesn't wake up her mom. She rips off the tape gagging John and forces him to drink an entire beer bottle. John tells her that she is delusional and talking to herself again and remembering things that never happened. He promises to help her with her psychosis if she will just let him go.
Sarah approaches with the knife, and uses it to unbind John's hands. He then takes the knife and cuts away the straps to his legs and stands looking at a weeping Sarah. He drops the knife to the ground and goes to embrace her, saying none of this is her fault. He then punches Sarah to the ground and denigrates her for being disobedient. He takes off his belt and begins whipping Sarah with it. Suddenly, he hears Peter moving behind him as Sarah lies unconscious on the ground as he beats her. He turns around to find a semi-conscious Peter on the ground, holding the knife at him. Peter tells John to leave Sarah alone and that what they did to her was wrong. John tells him to shut up and kicks the knife out of Peter's hand, mocking him for playing dead and saying that he always enjoyed the show.
Suddenly, Sarah says from behind that playing dead is a family secret. John turns to confront her, but Sarah swings a sledgehammer into his abdomen, knocking him to the ground. She raises the sledgehammer above her head, and brings it down hard on John. She then begins advancing on Peter, who begins crying and apologizing for not stopping her father and says that he never meant for things to get so out of hand. She stands over Peter, but then drops the sledgehammer. Peter lays there crying, and we see a pool of blood near John's lifeless body. Sarah walks out of the house, covered in her family's blood, leaving the boarded up house behind.
In sum, it appears that Sarah was actually the intruder the whole time, and that similar to the film Fight Club, split her personality into the active intruder and the passive victim, and the viewer saw events from the point of view of the peaceful/victim personality (although how she could have done everything in the film herself is a mystery to me). The little spectral girl was clearly the manifestation of Sarah's childhood self who was abused by her dad, and possibly/likely by her Uncle too. It is harder to determine whether Sophia was a real person whose visit triggered Sarah's repressed memories of abuse (and perhaps was abused as well) and later hallucinated by Sarah as some sort of safe harbor or was merely another physical manifestation of Sarah's fragmented personality the entire time.
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