Behind You (2020)

The story begins in 1979. Beth is with her boyfriend Charles in her room. Her little sister is wandering the house but Beth is hardly bothered since she's busy with her boyfriend. The next instant, the sister screams and Beth has to take Charles and look for her sister. They find her in a room, staring at the mirror and pointing.

As soon as they approach her, a pair of hands grab the sister from behind. Forty years later, two girls are taken to live with their Aunt Beth after their mother has passed away and their father is taking forever to come get them. The eldest is Olivia and the youngest Claire, who also has a stuffed toy bunny, through which she does her talking because she's traumatized by her mother's death. Aunt Beth clearly doesn't want the girls at the house and tells them not to go into her study or the basement. Claire's bunny agrees to follow the rules. Charles has prepared dinner for the girls and is a much better companion than Aunt Beth who is still frowning at the girls. He's made some weird stew that Olivia eats but Claire doesn't. When she's prodded to eat, she chokes on it because Charles has put peanut butter in the stew. Olivia stabs her sister's thigh with an EpiPen and saves her life. That night, Claire is beckoned by voices in the dark and told to do exactly what Aunt Beth forbid her to do. Claire enters the study and finds Aunt Beth Adler after drinking wine. She finds a box in the drawer, retrieves a key and heads to the basement. Olivia is sleeping peacefully through all this considering a few moments ago she had spotted something weird in the reflection of a mirror covered with paper in the bathroom. Claire finds the mirrors in the basement and someone begins writing in the dusty mirrors. Claire thinks it's her mother who wants to come back into the living world. She's told to repeat the words that will open the mirrors and help the spirits come inside. Claire says the rhyme thrice and sees something in the reflection. The next morning, Claire takes Olivia to the study and shows her a newspaper clipping that Aunt Beth has saved all these years because it is about her being convicted for killing her parents and sister. Olivia realizes they are in trouble and calls the woman, Camilla, who has taken charge of them. She agrees to come immediately. Olivia and Claire prepare to run away but the younger girl begins to act weird. Over dinner, she claims she wants to stay in the house and not go with her father. She's also feasting on dinner as if she's never eaten before. With Beth and Charles exchange uneasy looks. Beth already knows someone has been in her study because the box has been moved. The two quickly subdue the girls and separate them. Olivia awakens a little later and finds herself locked in a room. She looks out to see that the Camilla has arrived but is being sent away by Charles. Olivia bangs on the window but no one looks up. Later, Camilla returns and promises to help her out. Olivia confronts Beth and Charles, and Camilla enters with a gun that was in Charles' car. They get Claire even though Beth warns that "it" will not want to leave the house. In the car, Claire cries about leaving her bunny behind. Now that Beth and Charles are locked in a room, Camilla tells Olivia to get the bunny. Olivia doesn't find the bunny anywhere but comes downstairs to see it by the door. Olivia goes out and sees bloodstains on the car windows. Camilla has been killed and Claire is nowhere to be found. Olivia lets out Beth and Charles who reveal that the house is inhabited by an entity that wants to come into the living world. According to Beth, her sister killed her parents so she had to kill her in order to stop the entity from coming out. She says she happily took the blame for the murders but came back to stop the entity once and for all. Charles is still with her because Beth doesn't take his name during the investigation and he was allowed to live a normal life. Beth hopes there is another way to stop the entity rather than kill the body it wants to possess. They try breaking mirrors and use reflections to see the entity once they find out it can be hurt. That plan goes horribly wrong. Olivia finds Claire laying on a plastic sheet as Beth and Charles are getting ready to murder her. Olivia argues that Beth never really tries another way to defeat the entity and just likes to murder people. Charles is easily swayed by this speech and decides to help Olivia. Their plan is to feed Claire peanut butter so that she chokes. Then when the spirit leaves her, they will revive her with an EpiPen. It takes them around three EpiPens before Claire is revived. Olivia and Claire are getting ready to leave the next day. Charles is glib when he tells them Beth is in a sour mood because she was sure stabbing someone was the only way to defeat the evil. The girls are about to leave when they find the doors locked. Beth rushes to them and she claims that the entity is now caught between both worlds and can hurt them, which the entity does immediately by stabbing a piece of glass into Charles' throat. Claire thinks this is her fault and uses the words to get the evil inside her. Beth tells Olivia to stop her sister from doing so. Beth decides to be a martyr and says the word herself while handing Olivia a shard of the mirror. The entity enters like black smoke and possesses Beth. Olivia stabs her immediately. The police and ambulance arrive. Olivia is happy to be reunited with her sister. A police officer informs them that this incident would be treated as a murder-suicide. A candle burning inside the now isolated house suddenly blows itself off. (copied from Palvi Sharma's blog - Thanks)