Plot
In May 2015, struggling wedding videographer and film school dropout Gavin York finds a box of tapes labeled "Don't Watch" in the basement of his in-laws' newly purchased home. Intrigued, Gavin watches and makes an edit of the tapes with an outdated laptop.
The tapes comprise parts of a documentary from March 2004 by film students Sophia and Feldman. The two are trying to prove or disprove the existence of local urban legend "Peeping Tom," who can ostensibly be summoned by staring down the Ilchester Tunnel at midnight for an entire hour without blinking. Once Peeping Tom arrives, he gets closer to the victim each time they blink, ultimately forcing them to blink by fluttering his eyelashes against their face (a gesture colloquially referred to as "butterfly kisses") before killing them.
The students set up a camera and film the tunnel, reasoning that the camera will act as a human eye. Upon reviewing the footage, they discover Peeping Tom appearing in the camera's view of the tunnel. When Peeping Tom also begins to appear in whatever footage they film elsewhere, they realize that his presence has infested the camera itself; as turning the camera on and off emulates blinking, Peeping Tom gets closer with each clip they film. Feldman's mental state begins to deteriorate, and he is eventually murdered by Peeping Tom, forcing Sophia to continue the project alone.
Seeing a chance to break into a filmmaking career, Gavin hires a crew to chronicle his discovery of the tapes and his quest to prove Peeping Tom's existence. However, he fails to find any record of Sophia or Feldman's existence. The crew, headed by filmmaker Erik Kristopher Myers, begin suspecting that the footage is fake and was created by Gavin himself; their doubts only increase when they discover that Sophia and Feldman had previously won an award for a documentary in which they used an actor to portray a real person.
Unable to garner interest from news stations or local interest groups, Gavin posts the footage online and arranges an interview with a radio host to promote it. During the interview, Gavin is mocked by the station's callers, including The Blair Witch Project co-director Eduardo Sánchez, who dismisses it as an obvious derivative film. Gavin's obsession with Peeping Tom strains his relationship with his family, culminating in his wife leaving him after she discovers he used their son's college savings to fund his film.
Gavin instructs the crew to meet him outside the Ilchester Tunnel, where they find him attempting to recreate the Peeping Tom ritual with a camera. The crew begins arguing over whether or not to seek psychiatric help for Gavin, and the other staff accuse Erik of encouraging Gavin's descent into insanity by pushing him to continue working on the film. When they hear what sounds like Gavin running down the tunnel, they go to stop him, only to find that he has vanished, taking the camera with him.
Nine days later, Erik receives a package from Gavin containing a DVCam film, a separate, smaller parcel addressed to Sophia, Gavin's journal, and a hotel keycard. At the hotel room, the crew finds Gavin's corpse in the bathtub. After deliberating, they decide against showing the police their footage. Erik resolves to continue the project despite the rest of the crew imploring him to abandon it. Erik claims he wants to repackage the film as the story of Gavin rather than the story of Peeping Tom; when one crew member asks Erik if he believes Peeping Tom is real, Erik does not answer.
In additional footage, Sophia, while desperately attempting not to blink, recalls a dream in which she was easily able to stare down the tunnel for the whole hour, only to later realize it was not a dream and she had, in fact, actually successfully summoned Peeping Tom. She later claims Peeping Tom is right in front of her, but that she has found a way to defeat him, before shattering a glass picture frame with a hammer and using the shards to slice off her eyelids.
In a mid-credits scene, Sophia, now in an insane asylum, seemingly caresses Peeping Tom's face.
