In 2005 Katie delivers a box of old videotapes to her sister, Kristi,
 and Kristi's husband, Daniel. A year later, Kristi and Daniel's house 
is seemingly burglarized and the tapes are missing.
In 1988, a young Katie and Kristi live with their mother, Julie, and 
her boyfriend, Dennis, Kristi begins interacting with an invisible 
friend named Toby. Dennis notices that since Kristi's friend appeared, 
strange things have been happening in the house. Dennis and Julie try to
 make a sex tape, but are interrupted by an earthquake. While they look 
for the girls, the camera shows dust fall from the ceiling and land onto
 an invisible figure in the room. The figure then moves and the dust 
falls to the floor.
While reviewing the footage later, Dennis notices the strange 
incident. He invites his friend Randy over to view the footage, who 
suggests that Dennis place cameras throughout the house to capture any 
other incidents. That night in the girls' bedroom, Kristi wakes up and 
begins talking to someone off-camera before going back to bed. When 
Dennis questions her about this the following day, Kristi tells him that
 it is Toby. After more disturbed nights and strange occurrences, Dennis
 discovers a strange symbol in the girls' closet. He finds the same 
symbol on a picture of women in a book about mysticism. Dennis explains 
to Julie that the symbol belonged to a witches coven that brainwashed 
girls of child-bearing age into having sons and then forgetting about 
it, but Julie dismisses his claim.
 
After Kristi falls ill, Julie and Dennis take her to the hospital. Katie is left with Randy, and she asks him to play 
Bloody Mary
 with her. They go into the girls' bathroom and say "bloody Mary" three 
times and turn off the light. When nothing happens Katie insists they 
try again. Randy is stricken with pain and the lights reveal a large 
scratch up the side of his body. They try to leave the bathroom but a 
black figure moves past the door. When Randy tries to leave a second 
time, furniture is violently thrown around. After Julie and Dennis 
return, Randy hurriedly leaves.
The invisible entity terrorizes Katie and Kristi, harming Katie and 
later dragging her into the wardrobe until Kristi agrees to do what it 
asks. The next day Kristi asks her mother to take them to her 
grandmother Lois's home but she refuses. After Julie encounters 
terrifying activity in the kitchen she agrees to go to Lois's home. 
Dennis sets up another camera in the new bedroom. At 1 am, they are 
awoken by the sound of a car pulling up outside. Julie says the noise is
 Lois, who has trouble sleeping. After hearing more disturbances, Julie 
goes to investigate. When she fails to return, Dennis goes to look for 
her. In the background the camera captures a shadowy female figure. 
Dennis returns and picks up the camera.
He calls out for Julie and the girls but there is no answer. 
Downstairs, Dennis notices a human silhouette behind a curtain, which 
disappears when he enters the room. However he does find strange imagery
 on the walls, including the symbol that he found in the girls' room. 
Noticing that the back door is open, Dennis goes outside to investigate.
 In the garage he discovers Lois and several other women, all dressed in
 black. Dennis flees back to the house, with the women in slow pursuit. 
In the house he finds Julie at the top of the stairs. As he approaches, 
he sees that she is dead, her body levitating above the floor. Her body 
is thrown at Dennis, knocking him down the stairs. He picks himself up 
and sees Kristi, then retreats with her into a closet. Something bangs 
on the door but eventually leaves.
Dennis and Kristi leave the closet and find Katie crying by Julie's 
body. He slowly approaches Katie from behind and places his hand on her 
shoulder. As he does, Katie turns and unleashes an inhuman scream that 
throws him to the other side of the room, injuring his leg. Katie 
disappears. Dennis tries to crawl toward Julie's body but Lois walks 
into the hallway and stops in front of him. As Lois looks down on him, 
his body is suddenly and violently contorted, snapping backwards and 
killing him. Katie reappears and goes to Lois, who beckons to Kristi. As
 they head upstairs, Kristi calls to Toby. There is the sound of 
movement and a monstrous growl as the footage stops recording