College student Ethan disappoints his family by leaving dinner early to continue working on ELI, an experimental apparatus designed to generate wireless electricity. Ethan and his girlfriend Hannah sneak into their university's lab to activate the device, but hurriedly leave after the massive power draw causes a campus-wide blackout.The next morning, Ethan learns that his parents Richard and Lila were struck and killed by a truck. Ethan moves back home to help his younger brother Matt and little sister Becca adjust to life without their mother and father.Ethan continues working on his machine in the garage. Whenever Ethan activates the device, the siblings notice instances of apparent supernatural activity throughout the house. Although Becca also begins speaking to an unseen entity named Alice, the trio eventually becomes convinced that their mom and dad are trying to communicate with them.Having not spoken to her since his parents died, Ethan tells Hannah what he believes is happening and asks for her help tuning the machine. When he comes home, Ethan finds Becca's doll levitating as Becca and Matt play with an invisible presence. Ethan warns his siblings to not use the device when he isn't around and to not tell anyone what is happening.Next-door neighbor Tom, a widower who works for the DWP, helps Ethan rewire the house's electricity to provide more power to the device. With Matt and Becca's encouragement, Ethan continues working on the machine to make a stronger connection to the spirits.Matt's friend Dag comes over to the house. Ethan activates the device in the garage. Dag flees on his bike after encountering a shadowy specter. A presence nearly drowns Becca in the tub.Tom comes to see Ethan demanding to know what the device really does. Tom explains that because of the machine's signal radius, he has been having encounters with a ghost he believes to be his dead wife Karen.Ethan and Matt press Becca for more details about her imaginary friend Alice. Becca explains that Alice used to live in their house and is afraid of someone named Henry.Hannah stops by to show Ethan footage from their university experiment that depicts a spectral figure in the background. Ethan and Hannah visit family friend Marie, who explains that Alice was a little girl who disappeared and her foster father Henry Gifford was suspected of being involved.A ghost lures Becca into a trunk by playing hide-and-seek with her doll. Becca discovers a passage leading to a hidden room in the house's basement where she is captured by a specter.Realizing the ghost isn't his mom or dad, Ethan rushes to the house with Hannah. Ethan discovers the device is gone. While Ethan goes next door to confront Tom about the missing machine, Matt and Hannah frantically search for a way to get to Becca.Matt and Hannah become separated. Matt ends up in the hidden chamber captured by the same entity as his sister.Desperate to continue communicating with the figure he believes to be his wife, Tom refuses to let Ethan have the machine back. The two men fight. Ethan eventually convinces Tom that the ghost is not Tom's wife and he needs to get free to rescue Becca. Tom relents only to be pulled away by the apparition.As a dark figure approaches Matt and Becca in the other house, Ethan smashes the device at Tom's. The entities vanish. Ethan helps Tom recover before reuniting with Matt, Becca, and Hannah.Ethan, Matt, and Becca move out of the house and into a new place. Although Becca purposefully leaves her doll behind at the old residence, it mysteriously resurfaces in a moving box.