Jacob Singer, a Vietnam War veteran, struggles to maintain a grasp on reality as he experiences horrifying hallucinations and fragmented memories. Working as a postal clerk in New York City, Jacob is haunted by disturbing visions of demonic creatures and nightmarish scenarios, which blur the line between his traumatic past and his present life. Seeking solace, he turns to his girlfriend Jezebel, but her support is limited as she becomes increasingly concerned about his deteriorating mental state. Jacob's flashbacks to combat, coupled with the mysterious death of his son Gabe, add layers of confusion and despair, making it difficult for him to distinguish between reality and fantasy.

Desperate for answers, Jacob seeks help from his old army buddies, only to discover they are experiencing similar horrifying episodes. He consults his compassionate chiropractor, Louis, who offers cryptic insights into spiritual enlightenment and suffering. In his quest for clarity, Jacob confronts various authorities, including a suspiciously secretive government and medical professionals, who provide him with unsettling and contradictory information. As Jacob delves deeper, his journey becomes a harrowing exploration of his own psyche, leaving him grappling with themes of death, guilt, and redemption.