Oculus (2013)

The film takes place in two different times: the present and 11 years earlier. The two plot lines are told in parallel through flashbacks.

In 2002, software engineer Alan Russell moves into a new house with his wife Marie, 10-year-old son Tim, and 12-year-old daughter Kaylie. Alan purchases an antique mirror to decorate his office. Unbeknownst to them, the mirror supernaturally induces hallucinations. Marie is haunted by visions of her own body decaying, while Alan is seduced by a mysterious and ghostly woman named Marisol Chavez who has mirrors in place of eyes.

In 2013, Tim is discharged from a psychiatric hospital, having been convinced that there were no supernatural events involved in his parents' deaths. Kaylie has spent most of her young adulthood researching the history and perceived powers of the mirror. Using her position as an employee of an auction house, she obtains access to the mirror and has it transported to the family home, where she places it in a room filled with surveillance cameras and a "kill switch" — an anchor attached to the ceiling on a pivot, positioned to swing down and smash the mirror. Kaylie intends to destroy the mirror, but first wants to document its power, proving both Alan's and Tim's innocence.

Over time back in 2002, the parents become psychotic: Alan isolates himself in his office and Marie becomes withdrawn and paranoid. All of the plants in the house die, and their family dog Mason disappears after being shut in the office with the mirror. After Kaylie sees Alan with Marisol, she tells her mother and the parents fight. One night, Marie, distraught over her husband's apparent affair, tries to harm the mirror, finally becoming possessed by it, and attempts to kill her children, but Alan locks her away. When the family runs out of food, the children realize that their father is now permanently under the influence of the mirror too, so Kaylie goes to seek help from their mother and finds her chained to the wall, acting like an animal. Kaylie and Tim try going to their neighbors for help, but the neighbors disbelieve their stories. When Kaylie attempts to use the phone, she discovers that all of her phone calls are answered by the same man.

The fully possessed Alan eventually loads up a gun previously purchased by him and unchains Marie, with both parents attacking the children. Marie briefly comes to her senses, only to be shot dead by Alan. The children try to destroy the mirror but it tricks them, making them believe they are hitting the mirror when they are actually hitting the wall. Alan also experiences a moment of lucidity and kills himself by forcing Tim to pull the trigger of the gun and shoot him, causing a small crack in the corner of the mirror in the process. Before dying, he begs the children to run, but Marisol and other victims of the mirror appear as ghosts. The police arrive and take Tim into custody. Before the siblings are separated, they promise to never forget what happened with the mirror, one day reunite as adults and destroy it. As Tim is taken away and put behind bars, he sees the ghosts of his parents watching him from the house.

Back in 2013, Tim attempts to convince Kaylie that she is wrong and the siblings argue. When they notice the houseplants begin to wilt, they review the camera footage and see themselves performing actions they do not remember doing. Tim finally accepts the mirror's supernatural power and attempts to escape the house with Kaylie, only for the pair to be drawn back by the mirror's influence. Seeing a hallucination of her mother, Kaylie stabs it in the neck, only to realize that she has stabbed Michael Dumont, her fiancé and one of her fail-safes, who has come to check on her. They try to call the police, but are only able to reach the same voice who spoke to them on the phone as children.

At this point, they see their doppelgangers inside the house standing in front of the mirror. Realizing that the 9-1-1 call is not going through, they go back inside the house. Kaylie and Tim begin hallucinating by seeing younger versions of themselves, the past and the present merging into each other. They are separated and each of them relives the nightmare from their youth. Tim awakens alone in the room with the mirror, while simultaneously a younger Kaylie hallucinates her mother beckoning her from the mirror.

Tim releases the anchor, unable to see that Kaylie is standing before the mirror, and inadvertently kills her instead of destroying it. The police arrive and arrest Tim, who is hysterical, just as they did when he was younger. As both a boy and an adult, Tim claims the mirror is responsible. As he is taken away, Tim's adult incarnation sees Kaylie's ghost standing in the house with his parents.