Inner Demon tells the nightmarish tale of a teenage girl, Sam, who is abducted by a serial killer couple. Sam manages to escape and find refuge in an isolated farmhouse, only to discover it is home to greater terrors and a malevolent spirit. Hiding in a cupboard, bleeding to death, and waiting for her chance to escape, Sam is propelled into a struggle for survival, one that will push her to the limits not only physically and emotionally, but spiritually.