An international co-production of Spain, Argentina and Uruguay, the film stars Belén Rueda and Eva de Dominici.

Set in the 1980s,[1] the plot follows Bianca, an actress joining a theatre group led by Alma Böhn that is preparing a stage play employing experimental methods pertaining long sleepless periods to unlock higher degrees of perception.

[1] Dennis Harvey of Variety considered the film to be "too glossy, contrived, and dependent on rote jump scares to raise much of a fright", likewise featuring an "uninspired, workmanlike execution".

[6] Beatriz Martínez of Fotogramas deemed the film to be "a great piece of psychological horror", highlighting the film's "hallucinogenic atmosphere", the director's work and the performances of Eva de Dominici, Belén Rueda and Natalia de Molina, while citing the "somewhat confusing" climax as a negative point.

[5] Raquel Hernández Luján of HobbyConsolas scored 58 out of 100 points ("so-so") highlighting the first hour, displaying "brilliant ideas" and actresses "fully involved in their roles", especially Natalia de Molina, while decrying the badly resolved last part, "nearing on the laughable" and the grotesque.