After the tragic death of his wife, Jon immediately starts an affair with the enigmatic Red. The closer he gets to her, the more is his life dominated by an ominous digital signal - the stutter.

An international group of film students finds a disturbing video clip on the dark web which seems to contain poltergeist phenomena. Agreed that it's just what they need for their latest documentary project the group travels to the sanatorium shown in the video clip. Once there, they rig up their camera equipment and start to explore the possible ghost activities - until the true horror begins.

In 1697, an exorcism on the young French girl Rapunzel Gothel in Germany failed. The girl was killed, but the demon continued to live in the castle of Father Petrosinus, who carried out the exorcism and sold the building shortly afterwards. Centuries later, one of the last relatives of the priest enters the castle. Alina Grimm and her friends want to shoot their final student film, a horror movie, in the castle. Unsuspecting that their presence will conjure up Rapunzel Gothel's demon again, they roam the castle to take test shots for their project. But the demon wants revenge... and if he can't have the Father, then at least a relative of the same blood.