Catherine Deane is a child psychologist who uses an experimental virtual reality therapy to enter the minds of her patients. She is recruited by the FBI to use this technology on a comatose serial killer named Carl Stargher in a desperate attempt to locate his latest captive, who is still alive but will die soon if not found. Carl's twisted psyche proves to be a dangerous and surreal landscape filled with disturbing imagery, posing a significant challenge to Catherine as she navigates through his inner world.

However, as Catherine delves deeper, she unlocks Carl's traumatic past, making it increasingly difficult to separate her own identity from his horrifying experiences. Racing against time, she must find crucial clues and bring them back to the conscious world, working alongside FBI Agent Peter Novak. The deeper she goes, the more perilous her mission becomes, risking not just her life but also her sanity while trying to rescue the innocent victim before it's too late.