In 2007, Sally Sparrow enters the dilapidated house, Wester Drumlins, to look for subjects to photograph but instead finds eerie angel-like statues, a Yale key hanging from one of their hands, and messages from "the Doctor" behind the peeling wallpaper addressed to her, warning her of the "Weeping Angels". Sally returns the next day with her friend Kathy Nightingale to explore further; Kathy disappears as at the same time a young man claiming to be Kathy's grandson delivers a letter to Sally. The letter from Kathy explains, just moments ago from Sally's perspective, Kathy suddenly found herself in the 1920s in Hull, settling down with a husband and leading a peaceful life, and requests Sally to let her closest relative, her brother Larry, know of her disappearance.
Sally visits Larry at a DVD rental store, and finds that he has documented a series of "easter eggs" across seventeen unrelated DVDs, each with the same man calling himself "The Doctor" having half of a conversation with the viewer. Larry gives Sally a list of the DVDs as she leaves for the police station. There, she meets Detective Inspector Billy Shipton, who explains that there have been several disappearances at the Drumlins, and shows her an impound lot containing vehicles abandoned near the Drumlins, including a locked fake police box. Sally leaves, but remembers the key she found, and returns to find Billy has disappeared. She immediately receives a call from a much older Billy at the hospital and visits him. Billy explains after she left he found himself facing the Angels who were trying to retrieve the police box. Billy then suddenly found himself in 1969 and met the Doctor, who asked him to relay a message to Sally decades later; Billy subsequently married and started a video production house and was responsible for putting the easter eggs on the DVDs. Before Billy dies, he tells Sally the Doctor's message to her: to look at the list of DVDs. Sally discovers that the list is her own DVD collection, and realises the easter egg is meant for her.
Sally and Larry return to the Drumlins with a portable DVD player, and watch the entirety of the easter egg. Sally discovers she can converse with the Doctor as, in the past, he possesses a complete version of the transcript that is currently being compiled in the present by Larry as he watches. The Doctor explains that he and Martha Jones were transported to the past by the Weeping Angels, beings that feed off the potential time energy of others. The Angels are "quantum locked", allowing them to move incredibly fast when unobserved but cannot move when watched, and thus warning Sally not to blink when they are around. The Doctor tells them they are seeking his TARDIS to acquire its potential power which could be catastrophic. When the Doctor comes to the end of the transcript, Sally realises Larry has stopped writing it due to the presence of an Angel in the room, and the two quickly escape to the basement. There, they discover the Angels have brought the TARDIS, and Sally and Larry take shelter inside it as the Angels surround them. Inside they learn that the DVD can be used to activate the TARDIS; upon doing so the TARDIS dematerialises, leaving the two of them behind. However, with the TARDIS gone, the Angels have been tricked into observing themselves, permanently frozen as statues staring at each other.
A year later, Sally and Larry have become romantically involved opening a DVD and book store together, though Sally's insistence on keeping a folder of the events for the Doctor worries Larry. As Larry steps out for an errand, Sally sees the Doctor and Martha hurriedly leave a taxi in front of the shop, carrying a bow and quiver of arrows, and goes to meet them. When they do not recognise her, she realises that they have yet to experience the events that sent them to the past, and hands over her folder of information, warning the Doctor he may need it in his future and completing the ontological paradox. The Doctor and Sally say their goodbyes as Larry returns, surprised to see the man from the easter egg. Sally and Larry return to the shop hand in hand. The episode ends with a repeat of the Doctor's warning to Sally, this time directed at the viewer, overlaid with flashes of famous bronze and stone statues.