Welcome to the Original Nightmare...
Alice is a rational-minded sleep doctor, haunted by the mysterious nocturnal death of her younger brother. During a routine examination on a traumatized family with sleeping problems, Alice is forced to abandon scientific rationale and accept that the family is being terrorized by a parasitic demon who feeds on the weak while they sleep. In order to defeat the dark spirit Alice must journey into her own nightmares and confront her childhood demons.