Samuel Salomon, a literature professor, has been off work for almost a year after the tragic death of his girlfriend. Samuel has been suffering from a recurring nightmare in which a woman is brutally murdered by a strange ritual. Suddenly, the same woman who appears every night in his dreams is found dead in exactly the same circumstances. Samuel sneaks into the crime scene and there he meets Rachel who has also dreamed about the murder. Together, they will do whatever they can to discover the identity of the mystery woman, entering a terrifying world controlled by the figures who have inspired artists throughout time: The Muses.

A group of teenage girls are terrorized by Sister Ursula, a nun that believes she must rid the world of all sin. After Sister Ursula mysteriously disappears, the Catholic school is shut down. Many years later, the women, all grown up, are terrorized by a ghostly nun. The daughter of one of the women sets out to find out what happened all those years ago.

There's something in this house... Something ancient and dark that remains still, hidden and silent. It can only wait, having been concealed in the shadows for years. In fact, its milieu is darkness. Only in it can it show itself and move. It even takes its name: DARKNESS. It's lived here since someone tried to call it, more than forty years ago. Because this house hides a secret, a terrible past, an inconceivably evil act... Seven children, faceless people, a circle that must be completed. And blood, lots of blood...

As the new night nurse at a soon to be abandoned children's hospital readies the last group of orphans to leave, it becomes increasingly clear that these are not normal children. Something living in the hospital, something the children call the "mechanical girl," has a terrifying hold over them and will stop at nothing to keep them in the hospital with her forever.

The medical Dr. Owen leads a three-men SWAT team inside the sealed off building to get blood sample from the girl Medeiros to develop an antidote. They are attacked by the zombie-like creatures and Dr. Owen locks a zombie inside a room using a crucifix. He discloses that the patient zero was possessed by the evil and the Vatican sent him to save mankind. Further, they will only leave the building under his voice command. Meanwhile, three teenagers follow a fireman and a man that breaks into the building through the sewage system to rescue his colleague and daughter respectively and they are trapped inside. They are lured and release the evil creature that was locked by Dr. Owen in a room. Out of the blue, the lead team meets the journalist Ângela Vidal hidden inside the building.