The principal photography begun at the 10:00 am, and ends the same day, at 8:00 pm.
The final scene from "The Burial" can be seen a few seconds on the televisor, when Alice is watching it.
The name of the TV channels that shows on the TV, are named in honor the 'company' name.
The first time that The Man calls Alice, is at 17:59, and his last calls happens at 27;59.
The original script from the film, features more technology and physic theory's, with a single touch of supernatural thriller at the end, but it was changed with minus technology and more suspense.
The post-credits scene was the real ending for the movie, but the idea was dropped.
The movie can be divided in 5 main points: Incubi: translate as a 'Nightmare' (The beginning of the film) Yaxche: 'door to the other world' (When she goes out the house, the door was 'open') Dybbuk: an 'evil spirit' (The first call from The Man) Cadejo: a good spirit hidden in an evil aspect (The Police is calling her, worried from the origin of the calls) Valencia: the opposite feelings from the character (At the beginning, she was happy because the family pay a lot of money, to the end, she is scared)
Originally, the whole film will feature some tracks from the "10 Cloverfield Lane" music from the motion picture, from Bear McCreary, but the idea won't fit in the directors conception for a "true story". Anyway, some notes from the track "Michelle" and "10 Cloverfield Lane" can be eared in some parts of the movie.
The final quote in the film is "Don't look back", what supposed to be the tagline for the second installment of Valencia ("Chapter II")
In March 2017, the director say that this film can be the first part of many other parts, that can be united in an Urban Legends Universe, in which every part, feels a different part from the others, but it really fits in every one.
The screenplay for the sequel, was written by Nicolás de Jesús, Amayrani Luna, Juan de Dios Islas y Luis Arenas, and it was 100% acclaimed by those who can read it, calling the idea like "The Twilight Zone" meeting "Gossebumps" and "American Horror Story".