A little girl is adopted by a beautiful wealthy family that already has two children, and immediately appears as a prodigy as well as a very polite child. However, he has something strange, and his secrets begin to disturb his mother and frighten his illegitimate siblings.
The Coleman family has an unbridgeable void. Despite two children and a solid economic situation, an abortion left a wound and the answer seems to be the adoption of little Esther, a girl of about 12 who shocks them at the orphanage with her wit and her candor. Once with them, however, many small incidents happen and Esther is always at the center of the problems, not hiding from her acquired brothers her evil instincts and the precise plans behind every move. The concern is such that the parents decide to inquire about her past but at the orphanage they have no information about her prior to her arrival.
There is nothing more frightening than the idea of ​​having someone you do not know well and that over time turns out to be more and more disturbing. Living together with a deviant element that manages to turn us against our loved ones has always been a spark that triggers anxiety, as well as the theme of the demonic child (both metaphorically and actually) capable of passing for innocent in the eyes of all and making people believe crazy those who accuse him. Jaume Collet-Sera invents very little about this system by stealing suggestions from The Innocence of the Devil and a lot of recent Spanish horror. His idea of ​​suspense is not only quite obvious but at times also deceptive.
Long moments of silence interrupted by sudden noises, slamming doors, cars honking or surging in the soundtrack are the main means to increase the tension even when a deception is revealed, that is when the great fear of the protagonist (and of the spectator ) is for something that happens. Unfortunately, all this is not a prerequisite for anything else, a fear as an end in itself without there being any real construction of a lasting fear.
Only the final twist manages to give some unexpected thrills and a sense of anxiety about children and their way of learning and stirring the notions that surround them that manages to accompany the viewer even outside the room. But it is still a small thing.