The story revolves around a haunted farmhouse Mantra Nilayam, which is owned by Mantra (Charmi). She tries to sell the house but due to mysterious deaths at the house, nobody comes forward to buy it. A professor, however, agrees to buy the property on the condition that someone stay in the house for three months. Hero (Sivaji), a goon who looks after land settlements, is ready to stay in the house for the commission promised once the house is sold. The remainder of the film involves how Hero solves the mystery behind the deaths.

The movie is about engineer named Mantra, who shifts to Hyderabad after landing a job. When unidentified goons attempt to murder her, she seeks help from her friend.

Diary is the sequel of movie ‘Mantra’. It is a suspense thriller movie that revolves around the story as a witness to a sequel of mysterious incidents.