The Sender is a 1982 horror film directed by Roger Christian and written by Thomas Baum. A young man has just been admitted to a mental hospital after attempting suicide at a public beach. Unable to remember even his own name, the doctors call him John Doe #83. Soon after his arrival, the doctor assigned to him begins seeing and hearing things around him that have no explanation. Soon he begins to make the terrifying connection between the things he is seeing and his new patient.