Guillem Morales directs this Spanish horror/thriller. Belen Rueda stars as Julia, who is left bereft when her blind twin sister Sara (also played by Rueda) dies in mysterious circumstances. As Julia probes into the mystery surrounding her sister's death, she is hindered in her quest by the police, who are convinced that Sara committed suicide, and also by a series of small stress-induced strokes that are causing her to lose her own sight.