Look-alike twins Prem and Arun Kumar live a middle-class lifestyle. When they grow up, Prem decides to be celibate, becomes a Catholic Priest, and re-locates to a small village, while Arun becomes a Police Officer in the region. Years later Prem is a well-respected Priest, while Arun is the Superintendent of Police. One day Prem visits Arun with regard to the incident of a young woman named Mary who had reportedly killed herself. He asks Arun to have the body exhumed in order to perform a postmortem. Arun suspends the Police Inspector who had Mary`s body buried without following proper procedure, and goes to the graveyard to have the body prepared for a postmortem. When the coffin is dug up and opened Arun gets a shock when he finds that the dead person in it is Prem. He immediately begins an investigation (Tahqiqaat) to find out who killed Prem, and what happened to Mary`s body.