Sleep paralysis is a serious sleep disorder linked to extreme hallucinations that feel very real. People who suffer from this relatively obscure and often misunderstood disorder have the most horrific experiences just before falling asleep or during the night. A number of them talk about this in The Nightmare. For some of them, it started without any demonstrable cause early in childhood; others make a link to a lack of love during their early lives or a problematic adolescence. Initially, the symptoms seem like “ordinary” nightmares – but the stories become ever more extreme and terrifying. The interviewees talk in great detail about the presence of an evil spirit, sometimes in the form of a man with a hat, a shadow or more abstract frightening figures. This evil spirit talks to them – there are frightening sounds and sometimes even physical pain caused by instruments of torture. All sufferers explain that they are unable to move or to talk – which makes the experience all the more terrifying. The film brings their stories to life in a very realistic way: the interviews are held in dimly-lit bedrooms and the stories re-enacted with all the resources of a horror film director, leading to the birth of a new sub-genre: the horror documentary.