Land of fear (2000)

A story about a police officer who was assigned to a secret mission as an undercover drug dealer, with the license to kill, deal in drugs, and do whatever is required for his identity to remain secret, with the ultimate purpose of reporting back to his supervisors. Gradually, after years of losing grip over his mission and purpose, realising that being a drug dealer has become his true identity, and that he hasn't heard back once from his supervisors, he then goes and tries to contact them back, only to realise that the designated postman had never delivered back any of the reports to his supervisors, let alone is aware that they exist.