A young woman, Sally Sparrow, approaches Wester Drumlins, an old house in London. Fascinated by the past, she goes inside and starts taking pictures, then notices a piece of torn wallpaper. Pulling it aside, she finds a warning about the “Weeping Angels,” addressed specifically to her. It tells her to duck several times, and finally she ducks… just in time to avoid a rock thrown through a window. She looks to see nothing but a stone statue of a weeping angel outside. Pulling aside the rest of the wallpaper, she finds the note signed “The Doctor—1969.”
Sally goes back to her flat and comes face to face with her roommate’s brother Larry, completely naked. He’s been watching videos of a cryptic man talking at random on various DVDs: the Doctor, accompanied by Martha. Sally’s roommate, Kathy Nightingale, quickly gets rid of him and offers to go with Sally to check out the house.
Outside they notice the statue from the previous night… but it appears to have moved. Sally and Kathy go inside and find nothing, until the doorbell rings. Kathy hides in an adjacent room in case something goes wrong, while Sally opens the door to meet a young man who addresses her by name. While Sally talks with him, Kathy hears a noise but is unaware that an angel statue changes position each time she looks away… and it’s getting closer. Outside, Sally hears a noise and finds that Kathy has vanished.
Kathy finds herself in a cow field and talks to a young man, Ben Wainwright. He says that she’s in Hull, not London, and his newspaper says it’s the year 1920. She heads off for the nearest town while he follows her, curious.
Sally talks to the man, who identifies himself as Malcolm Wainwright. He has a letter for her… a letter from Kathy Nightingale, his grandmother who died two years ago. The photos with the letter show that Kathy is Sally’s Kathy, and the letter is from Kathy as well. Kathy has written that she was transported back into 1920, married Ben Wainwright, had three children and numerous grandchildren including Malcolm, and made Malcolm promise to deliver the letter at this specific day and time. A puzzled Sally runs upstairs and finds four of the angel statues, with one holding a Yale key. She takes it then goes after Malcolm who has fled the house… unaware that one of the statues behind her had shifted position and was reaching for her despite being solid stone.
Sally continues to read of how Kathy wants her to give her love to her brother Larry, who works at a secondhand DVD store. Sally goes there and finds more TVs playing with recordings of the Doctor speaking random sentences. Larry admits that he and other Internet nerds found the messages, which appear on 17 different DVDs and no one knows how they appeared there. He leaves for a moment and Sally makes a random comment… which the Doctor on the DVD seemingly answers. They have a brief “conversation” before Larry returns, and a flustered Sally goes to the police.
Once Sally mentions the house, DI Billy Shipton agrees to meet with her. He’s clearly attracted to her and starts flirting, then takes her down to the abandoned car lot where a number of empty vehicles have been found near Wester Drumlins over the years. They’ve also found a police box: the TARDIS. Billy says it’s a fake and they can’t get the Yale lock to open. He asks Sally for her number and after giving it, she takes off, flustered. Billy turns to find the TARDIS surrounded by four angel statues. He goes up to one, examines it, then blinks…
… and finds himself in 1969. The Doctor and Martha come up and the Doctor explains that he has built a time detector to locate him when he arrived. The Doctor then further explains that the Weeping Angels are an alien race from the beginning of time. They feed by sending their victims into the past, then consuming their untapped temporal potential. The Doctor says he needs Billy to give Sarah a message… but it will take a while.
Outside the police station in the present, Sally realizes that she has the key from the house and it might fit the TARDIS. She goes back to the lot only to find that Billy and the TARDIS are both gone and the door is burst open. She then gets a cell phone call from Billy, asking her to meet him at a hospital. She goes there and finds Billy, now 45 years older and on death’s door. He explains that the Doctor wanted him to tell her to “look at the list,” and that after 1969 he went into publishing and then DVD production. He was the one who put the Doctor’s message on the 17 DVDs… and the list shows that they are the only 17 DVDs that Sally owns. Billy reveals that he is to die that night but that he held on so that he’d have one last chance to see Sally.
Sally heads for Wester Drumlins while calling Larry to meet her there and bring the DVDs and a DVD player. They play the video there and the Doctor’s random sentences now come together as his half of a conversation responding to her. Larry starts transcribing everything, and the pre-recorded Doctor “explains” that he used the transcript to know what she was saying and respond to it himself. He then explains that the Weeping Angels are an alien race that exists in a quantum-locked state. As long as they are observed they are invulnerable stone statues. However, if no one sees them they can move quickly and send their victims back through time. They cover their eyes so that they don’t accidentally see each other. The Angels want the TARDIS to feed on its temporal potential and could disrupt the solar system if they fed unchecked.
The DVD conversation ends as the Doctor warns that the transcript ends and he figures the Angels attacked at that point. He warns them not to blink and good luck, and that’s the end of the recording. Sally and Larry turn just in time to stop an Angel from touching them. Sally tries to find a way out but the doors are locked, while Larry tries to watch the Angel without blinking. His nerve finally runs out and it gets within a hairsbreadth of touching him.
The doors are locked but Sally finds the cellar where Larry joins her. The three remaining Angels are there, surrounding the TARDIS. Sally and Larry try to get the door open, but the fourth Angel arrives between glances and causes the light bulb to flicker. With each flicker the Angels advance closer, but Sally manages to get the door open just in time.
Inside, the ship shakes as the unobserved Angels shake the TARDIS back and forth. A security protocol detects their presence and a hologram of the Doctor appears to tell Larry to put the DVD in the console. When he does so, the TARDIS dematerializes, leaving Sally and Larry behind. However, the surrounding Angels have no choice but to look at each other when the TARDIS disappears… and they’re frozen into immobility by each others’ looks.
A year later, Sally and Larry are running the DVD store together. Sally has been keeping a file of the Angels and everything she did, along with Larry’s transcript. She realizes the time has come when the Doctor and Martha get out of a taxi outside, on the trail of some other alien threat. She quickly gives the file to the Doctor, who understands that something is happening out of sequence. He thanks her and leaves.
After it’s all over, the Doctor’s DVD warning plays again… while pictures of statues from around the world are shown.