According to producers Joaquin Padró, Mar Targarona, and Marina Padró, the Casademunt film was shot on a moor in the province of Teruel, whose location is "a vital ingredient to delve into history."
The music recording sessions took place at the Polish S-3 TVP Studios in Krakow, where the Beethoven Academy Orchestra conducted by Diego Navarro, gave life for the first time to the soundtrack of the film. In the recording predominated the string section, with the participation of piano, celesta, harp, and flutes.
Directorial and Screenwriter debut of David Casademunt.
At around 29:00 minutes, Lucia and Diego are counting the seconds after a clap of thunder is heard in order to estimate how far the storm is moving away. This is similar to a scene in the film Poltergeist (1982), in which the father is doing the same so his son can put his fears aside.