A medical college student get possessed by a ghost that wants to take revenge on the college’s dean.

Vetri and Maya love each other. Vetri’s twin brother Shakthi wants to molest Maya, so he is thrown by his parents. A few years later, villains kill Vetri, his parents, and Maya. They return as ghosts and eliminate them one by one. Shakthi returns as a powerful tantrik and kills all the villains for his family’s dispute. He now uses his power to kill Vetri, and at the same time, wants to have sex with Maya as revenge. In the end, good wins over evil.

Thambi Vettothi Sundaram is set in Kaliyikkavila, a town set on the state border. This place has a unique distinction; almost everyone here is educated and quite peculiarly, almost every second person is involved in some kind of illegal business ranging from smuggling to the brewing of illegal liquor and other such activities. This place is certainly an antithesis for all those who believe that education is the one solution to all social evils. Here, people seem to be corrupt in spite of education. Sundaram (Karan) is one from the town, well educated, but not yet initiated into any subversive acts.