Two young sisters find that all the mirrors in their estranged aunt's house are covered or hidden. When one of them happens upon a mirror in the basement, she unknowingly releases a malicious demon.
The lives of six girls belong to different worlds although connected to each other through a doll called Molly, whose existence dates back to 1976, when she appeared among the rubble of the great fire of the San Carlos orphanage, in northern Spain.