José Sirgado, portrayed by Eusebio Poncela, is a disillusioned director of horror films battling heroin addiction, entrenched in a chaotic relationship with Ana Turner. Out of the blue, he receives a package from Pedro, the cousin of his ex-girlfriend Marta, containing a reel of film, an audio cassette, and the key to his apartment—despite having met Pedro only twice.
As José and Ana delve into the audio cassette, they are taken back through flashbacks of their encounters with Pedro. The first meeting occurred when José, alongside Marta, visited the family home to scout locations for his next film. Pedro, who is obsessed with creating homemade cinema, shares a moment of getting high with José while introducing him to time-lapse photography techniques. Fascinated, José sends Pedro an interval timer designed to enhance his filming process.
Their second meeting unfolds with José and Ana returning to watch Pedro's films together. In this visit, Pedro gifts Ana a nostalgic Betty Boop doll, stirring memories of her childhood. After this visit, José and Ana can't shake their curiosity and decide to watch the enigmatic film reel while listening to the remainder of the cassette. On the tape, Pedro recounts his life after utilizing the interval timer.
He describes a peculiar incident where, after dozing off, his camera mysteriously activates, capturing his sleeping form. Upon developing the footage, he finds a solitary red frame—an anomaly that intrigues him. Gradually, Pedro becomes dependent on this device; if he fails to film himself while sleeping, he grapples with withdrawal symptoms akin to those of heroin addiction. The rejuvenating experience of awakening post-filming leads him to believe that the peculiar occurrences during the red frames have some significant importance.
Curiosity peaks as he enlists Marta to observe him during his sleep, resulting in a haunting moment where the camera independently shifts focus to her, leading to her inexplicable disappearance. As Pedro approaches the end of his film, with only one frame remaining before the footage turns entirely red, he sends everything to José—his film, the audio instructions, and the apartment key—requesting him to come over and develop the final reel.
Upon arriving at Pedro's apartment, José finds it desolate. The final film reveals an alarming sequence of red frames, save for a single shot that captures Pedro’s face. To José’s astonishment, this image appears to animate, with Pedro subtly gesturing toward the bed and urging him to partake in the same intensified experience. The image then blurs, shifting seamlessly into José’s own face, mirroring Pedro’s gesture. Ultimately, the film culminates in an unexpected twist as José succumbs to the allure of experiencing the same transcendent "rapture," retreating into Pedro's bed to embrace the phenomenon that has captivated them both.
