"Ascher makes a persuasive case that it is the physiological phenomenon of sleep paralysis that has created the nightmare tropes now commonplace in art and literature: they are recognisable, diagnosable symptoms. This condition, he says, both pre-exists and is the inspiration for scary movies such as Nightmare on Elm Street – and not the other way round. It also accounts for alien-abduction delusions. However, his film also listens sympathetically to sufferers who interpret their condition in spiritual terms. He films his interviews and reconstructions in a self-consciously creepy way; it's possibly a bit overdone, but often disturbing, especially the dream where the man gets a call on his mobile phone from a polite voice saying: "I wonder if you can do me a favour?" I jumped." - Peter Bradshaw, The Guardian