A late-night radio talk show host named Charlie Crowe discovers reports of mysterious deaths associated with sleep paralysis and eerie human-like figures known as "shadow people." Skeptical but intrigued, he begins to investigate, diving into disturbing stories and interviews that describe the terror experienced by victims. As he delves deeper, he learns about an ancient legend stemming from Cambodian refugees, who attribute these shadowy apparitions to an age-old curse that causes unexplained deaths during sleep. The sudden rash of deaths and his own frightening encounters start to erode his skepticism, prompting him to challenge scientific explanations and accept the possibility of a supernatural phenomenon.

Charlie's obsession with uncovering the truth leads him to collaborate with a medical researcher, Dr. Sophie Lacombe, who initially dismisses his findings but eventually joins his quest after witnessing inexplicable events. They uncover a trail of evidence that hints at a sinister conspiracy and the potential that these entities are more than just a psychological manifestation. As deaths rise and the shadow people seem to grow more aggressive, Charlie and Sophie race against time to find a solution that could save countless lives, all while fighting their own terror as the shadow people close in on them.