Directed by Guillem Morales. Starring Belen Rueda, Lluis Homar, Pablo Derqui, Francesc Orella, Joan Dalmau, Boris Ruiz, Andrea Hermosa, Julia Gutierrez Caba 16 cert, limited release, 117 min

IT’S HARD to know what to think when you see the phrase “Mr Great-Director presents” on a film’s poster. Often it merely indicates that the distinguished man encountered an up-and-coming tyro on the same escalator.

But those horror films endorsed by Guillermo del Toro – this is one – do tend to achieve a certain standard. One could, thus, be forgiven for approaching Guillem Morales’s Spanish shocker with some enthusiasm.

Well, it starts decently enough. The opening scenes find Sarah, a middle-aged woman who appears to be blind, hanging herself in a grimy basement. It transpires that both she and Julia (Belen Rueda from The Orphanage), the sister who survives her, are – or were – suffering from a degenerative eye disease. Despite increasingly severe fits of semi-blindness, Julia sets out to discover what led her sibling to take her own life.

In a scene that treads dangerously close to making monsters of the disabled, she goes among the attendees at centre for the blind and, while they mill sinisterly and nakedly about the changing room, listens unnoticed for titbits concerning her sister’s mental well-being. Later, despite the entreaties of her unwilling husband, Julia goes to a hotel where her sister stayed and starts to piece together the roots of her descent into despair.

It’s a great set-up. Layered with queasy greys, the picture’s ever darkening tone reminds us of the protagonist’s increasingly weakened vision.

Strange neighbours lurk on the other side of fences. Odd hums and creaks lead Julia down ill-advised corridors. The mind boggles as to how the film-makers will tie up all these dangling plotlines.

How indeed? A shocking twist arrives. Then that twist twists within itself.

Then two twists double back towards the first before twisting in an entirely new direction.

By the close of this overlong film, most sane viewers, wearied by too many revelations, will find themselves entirely unable to care – or discern – where the plot is going next. Del Toro completists will, however, not want to miss it.