Enquete en enfer

The private investigator Nicholas "Nick" Tordone is a man with a childhood problem since he saw his father committing suicide. His friend Dr. Frank Meyers works in the Fallbrook mental institution and was a great friend of his father. He helps Nick since he lost his father. When Dr. Meyers is found dead in the clinic after committing suicide, Nick does not believe and decides to investigate his death. He goes to Fallbrook as if he has amnesia and is interned in the clinic. Soon he finds that four patients are missing and his further investigation shows that all of them were suicidal inmates. He also discovers that the dangerous criminal Dr. Sullivan Rane is hidden in the clinic. What is happening in Fallbrook?