A video images shows a pregnant Kristi (Sprague Grayden) and Daniel (Billy Boland) are painting their nursery in anticipation of the arrival of their first son, Hunter. Kristi's sister, Katie (Katie Featherston), arrives to congratulate them and asks if she can drop off a few boxes she was left by their grandmother when she passed away. She leaves them boxes full of VHS tapes that were filmed when they were children. As she leaves, Daniel teases her about her relationship with her boyfriend Micah since they are moving in together.
One Year Later.
The house is a mess and Daniel is trying to document all the damage and any items that might have been stolen and goes down into the basement. While in the basement, the only thing he notices to be missing is the box of tapes that Katie left them.
On a videotape image, it's Katie's birthday, and there's a party. The year is 1988 as identified by the caption on the video image. Dennis (Christopher Nicholas Smith), the camera man, is a wedding videographer and has been dating Katie and Kristi's mother, Julie (Lauren Bittner), for the last few months. He records Kristi talking to herself by a little soccer net that they have set up, and he asks Julie to bring her over so that they can sing happy birthday to Katie. Kristi continues talking to her imaginary friend, "Toby" despite the insistence of her mother to play with the other children. Dennis films a video entry from each family member. Julie shows off Katie's cake while Julie's mother tells Katie that when she was born she laughed and cried. Dennis films himself thanking Katie for being so welcoming and despite the fact that he isn't her father, he loves her very much.
That night, Julie rolls a joint and Dennis decides it will be fun to record it. Despite the fact she wants to keep her kids from seeing it, Dennis convinces her to let him keep the camera on. Eventually, he convinces her that they should make a sex tape. However, at that moment an earthquake occurs and the couple runs to find the girls. Dust falls around the bedroom and outlines around the shape of something in front of the bed. It is there for a minute before the dust collapses. The outline is gone.
The next morning, Dennis is going over the footage and asks Julie to confirm what he's just seen. She asks him to delete the video, but he tells her that he needs to document this because hes certain that something was there. He recruits his friend Randy, a tech expert, to help him set up cameras around the house to catch whatever is happening.
That night, Dennis sets up a camera in both bedrooms to catch some paranormal activity. Kristi wakes up in the middle of the night and walks towards the cupboard, which can be heard creaking open. She starts talking about Dennis describing him as "nice". The next morning, Dennis asks her about the conversation, and she tells him that what she and Toby talk about is secret because she wants to stay safe. Dennis asks if Toby is threatening her, but she just says that she just wants to stay safe.
Dennis and Randy are discussing the camera equipment when Julie interupts them and asks how they are doing. After she leaves Dennis hears a noise. Randy hears it as well so they go to check it out. They end up in front of Dennis' closet. Dennis opens it, and out jumps Julie, wearing a witch mask. Dennis freaks out and has to sit down to calm himself while Randy and Julie laugh uncontrollably.
The girls are sleeping outside in a tent. Dennis checks on the girls to see how they are doing and brings them some snacks. Later Julie hears noises going on in the girls' bedroom so she assumes that the girls came back into the house. Dennis goes to check on them, but Julie then starts hearing noises from her bathroom. She starts walking towards the bathroom and the door to her bedroom starts to close slowly until it bursts open and Dennis can't find the girls in their room. They go down and try to get to the girls outside, but the door is locked. They unlock it and bring the girls inside. The next morning Dennis asks Katie, who is jumping on a trampoline, if she had snicked into the house last night. She says no.
Julie's mother expresses her disapproval of Dennis to Julie, citing his lack of affluence and wealth as a major area of concern as she wants her daughter to be financially secure. She asks Julie if shell ever have another child but Julie says she's fine with two beautiful girls. Julie's mother reminds her that she always wanted to have a large family and says that she shouldn't stop until she has a son.
Julie is outside with Katie, who is learning to roller blade. Randy is unloading his equipment and telling Dennis that he believes in ghosts, and that he might be missing most of the activity since it happens mostly at night. They discuss camera placement throughout the house. Dennis is showing Randy his oscillating fan idea for the camera. Dennis sets the oscillating camera up in the kitchen so that it can look into the dining room as well.
That night Kristi is seen running through the hall into the dining room where she positions a chair so that she can climb onto the table. The camera moves into the kitchen, when it returns to the dining room Kristi is gone. Kristi is seen sneaking up to her parent's room where she looks in, leaves and is seen again just through the door way. She is looking at something down the hall when she snickers and runs out of frame again. She is giggling as she runs back to her room. Katie is up and asks what Kristi is doing. She replies nothing and is told to go back to bed.
The next morning Julie finds Kristi in her room painting. She asks if Toby woke her up and told her to go downstairs to which Kristi replies no. Julie tells Kristi that she can tell her the truth, but Kristi tells her that Toby doesn't want her talking about it. Kristi then tells Julie to ask him herself since he's standing right next to her. Julie looks around and says she doesn't see him. Kristi replies "he's there".
Randy checks out a few books on entities and demons so that he and Dennis know what they are dealing with. Randy discovers that witches covens would make deals with demons and use young girls as the vessels through which young boys would be born. The children would then be brainwashed in order to do the demon's bidding. They find a photograph of a coven from the 1930s, each with a distinct insignia of an upside down triangle within a circle.
Julie wakes up for a midnight snack. She tosses the remnants into the garbage disposal but drops a spoon into the disposal unit. The light in the next room turns on by itself as Julie sticks her hand into the disposal unit and suddenly screams. The light has fallen with a crash and startled her. Everyone is woken up by the sound. Julie and Dennis tell the girls to stay upstairs and discuss what happened.
Dennis asks Kristi if he can join her tea party. He sets the camera down and goes to sit down next to Kristi. She tells him not to sit there because it's Toby's spot. He apologizes and sits down across from her. Dennis asks what the last thing Toby said to her and Kristi replies "secrets". Kristi moves her cup and accidentally touches Toby and quickly apologizes. Dennis asks why she is apologizing and Kristi explains that Toby doesn't like being touched. Dennis mockingly apologizes for her, explaining that it was an accident. He leaves the camera to record more of Kristi and Toby talking. Katie returns and starts making fun of Kristi, calling her a baby. She goes into the cupboard, which Kristi says is Toby's room, and the invisible demon slams the door shut and refuses to let Katie out. Katie starts screaming, but Kristi just says, "I told you not to go in there". Julie arrives and Katie bursts out of the cupboard screaming that Kristi locked her in.
Julie and Dennis decide to go out for the night and hire a babysitter to look after the girls. The babysitter plays around with them and jumps in front of the camera in the kitchen to scare Dennis before dressing up like a ghost and fooling around with the girls. After the girls are in bed, she goes downstairs to study. Someone comes downstairs with a blanket draped over themselves and stands behind the babysitter creepily. Before she turns around, the blanket collapses, empty. She is confused and brings the blanket upstairs when the invisible demon blows on her and scares her so that she stays downstairs the rest of the night. When the couple returns, the babysitter leaves immediately, obviously scared.
The next morning Randy and Dennis are reviewing the tapes and see the footage of the person in the sheet, and the babysitter being blown on. They are both astonished by the footage, Randy asks if he told Julie yet. Dennis says no in fear that she'll make him take down the cameras. Randy tells him to keep filming.
Kristi wakes up in the middle of the night and stands in the doorway of her parents room for a couple of hours. When she returns to her room she is seen talking to Toby and says "No, no, I don't want to talk to you anymore. I'm going to bed". Dennis goes to investigate the cupboard, he finds scribblings all over the wall. Dennis comes down stairs and sees Julie in the living room with Kristi. Julie says she is incredibly sick and that they need to take her to the hospital. Dennis and Julie take her to the hospital and Katie is left with Randy to look after her. She bullies him into playing Bloody Mary with her, and they do it twice. The second time, the demon scratches Randy across the stomach and begins overtly terrorizing them. Blurring shadows can be seen passing by the door. After Katie closes the door, the door starts to rattle. The demon starts slamming things outside the door which scares them. Randy tries to calm down Katie. Randy opens the door and sees stuff thrown in front of him, so he closes the door again and again tries to calm down Katie. Randy exits the bathroom to survey the room, to find that the demon has gone. He picks up the room and tells Katie that he won't tell her mom. When Dennis returns home, Randy packs up all his equipment and leaves because it's too much for him.
Dennis is at his desk reviewing the footage Randy told him to watch of the incident. Dennis is seen looking through a book and setting aside a picture. He tells Julie about the happenings and shows her a picture from the 30's and points out the symbol that looks like the one in the girl's cupboard. Kristi and Katie are running up to their room when Katie hits an invisible wall, and stares up like she's looking at someone. Julie and Dennis are arguing downstairs. Dennis tells Julie about the rituals that witches performed. Toby grabs Katie by the hair and yanks her off the ground. Dennis tells Julie to look at the tapes but she refuses. They continue to argue until Katie comes into the room crying. She tells them that Toby attacked her. Julie is mad and tells Dennis that the experiment is over.
Dennis is at his desk editing some tapes. Meanwhile the water is turned on in Julie's room as she sleeps. The sound of a door creaking open can be heard. Katie's bed sheets start moving, slowly growing in size over her until they fall down, waking her up. Things begin to move inside the room. The girls' teddy bear falls down, and Katie wakes Kristi up. Their Lite Bright turns on and is displaying the sign of the Witches Coven. Katie asks what's happening to which Kristi replies "Toby's here". More things start to move and Katie gets scared as she calls out for her mom. Kristi tells her to just ignore it. Suddenly, the cover is thrown at the camera, Katie tries to run downstairs when she is dragged across the room by an unseen force several times while she screams for Kristi to help her. Kristi screams at the demon to let her go, but it throws the bed around. Katie is dragged back into the cupboard until Kristi agrees to do what the demon asks. Katie is released and they both get into bed together.
The next morning, the girls beg their mother to take them to their grandmother's house to get away from Toby. Julie is in the kitchen talking to her mom when someone knocks on the door. She goes to see who it is, when she comes back the kitchen is empty. Suddenly, all the utensils and furniture fall from the ceiling, scaring Julie out of the room.
Dennis, Julie and the girls drive to Julie's mother's house. They eat apple pie when they arrive and Dennis sees Kristi fingering one of the paintings in the dining room. He tells her not to touch it because it might be expensive. As Kristi and Katie play outside, Dennis films Julie talking to her mother about what is happening. Kristi and Julie's mother play dress up, and Kristi puts on a wedding dress. When Dennis asks her who the lucky groom is, Kristi replies "Toby". This freaks Dennis and Julie out, and they put the girls to bed early.
Dennis and Julie are trying to get to sleep in separate beds when around 10PM she climbs into bed with him. Dennis hears something and wakes up Julie. She tells him it's her mother and that she's usually up because she can't sleep. The sounds get louder so Julie goes to see why her mother is being so loud. When she doesn't return, Dennis goes to find her. Julie's mother appears behind him for a moment, but he doesn't notice. He searches the house but can't find anyone. As he's searching for everyone, he hears something in the cage behind him. When he looks the bird is gone. He turns around and sees a silhouette of someone through a window. He checks to see who it was but no one is there. The pictures have all been set on the floor. Behind them are several witchcraft symbols, one of which is a pentagram. He goes out to the garage and finds a group of older women standing in a circle. He freaks out, running back into the main house and locking the door behind him. The women are seen walking towards him intently.
He runs around the house calling for the girls and finds Julie at the top of the stairs. Something is odd though as her expression is blank and she appears taller. He sees that she is levitating before she is thrown at him at full force and they fall down the stairs together. Julie is dead, and Dennis hears the whimpering Kristi who is in the dining room. He grabs Kristi and they run and hide in the closet for a few moments. Footsteps and the sound of slamming objects are heard outside the door. Dennis tells her that they need to find Katie. They walk through the house to find a way out but see a bonfire outside. They see Katie by the steps crying over the body of Julie.
Dennis tells Kristi to stay by the wall when he goes over. Katie turns around possessed and throws him across the room, breaking both of his legs. When he starts to crawl back into view, Julie's mother walks in front of him. The demon slams him down onto the ground as he tries to rise, then grabs him by his arms and legs and breaks his spine, contorting his body into unnatural shapes before letting him go. Julie's mother holds out her hand as Katie grabs it. They head up the staircase, and Kristi cheerfully calls out, "C'mon, Toby!" Julie's mother says "Let's get ready". We hear a faint animal growling sound before the camera goes black.