Demonologists Ed and Lorraine Warren confiscate the Annabelle doll from nurses Debbie and Camilla, who claimed that the doll often performed violent activities in their apartment. During the drive back home, the doll summons spirits to attack Ed, but he narrowly survives. Annabelle is locked in a sacred glass case in the couple’s artifacts room that is blessed by Father Gordon to ensure the evil is contained.
Sometime later, the Warrens welcome Mary Ellen, who will be in charge of babysitting their daughter, Judy, at the house while they travel overnight to investigate another case. At school, Judy notices the spirit of a priest that begins following her. Mary Ellen’s friend, Daniela, arrives uninvited to the Warrens’ home, who is secretly curious about speaking to the dead. She sneaks into the artifacts room and starts examining every item, ultimately trying to contact her late father. She abruptly leaves Annabelle’s glass case unlocked, and the terror begins shortly afterwards with the spirit of Annabelle “Bee” Mullins unleashed. That night, Annabelle begins releasing other spirits, such as the Ferryman, the Bride, a Feeley Meeley board game, and the Black Shuck.
Mary Ellen’s crush, Bob Palmeri, arrives outside the house and serenades her, but is later attacked by the Black Shuck and hides in the Warrens’ backyard. Mary Ellen is tormented by the Ferryman, while Judy is confronted by Annabelle in her bedroom. Daniela had left earlier but sneaks back into the house to return the artifacts room’s keys. She gets locked inside the room and tormented by various objects, such as a piano and an old television that can predict the near future. She finds the Mourner’s Bracelet and sees her father twisted into a malevolent spirit. A bloody and screaming Daniela appears on the television screen after having answered a cursed telephone. The real Daniela later unwittingly reaches to answer the telephone but is interrupted just in time by Judy and Mary Ellen.