It is basically an investigative film as CBI officer Kasi Viswanath (Vijaykanth) is entrusted to investigate the mysterious disappearance of Judge Sadasivam (Nassar). The Kasi Viswanathan team comprises junior officer Kesavan Nair (Anad Raj) and a constable (Pandiaraj). Soon Kasi finds out that a state minister Elakyam (Prakash Raj) is behind all crimes in the city and he is assisted by three senior cops. Suddenly one by one the bad cops are killed, with needle of suspicion resting on Kasi as a look-alike is behind the murders. It is revealed that it is a revenge killing by Perarasu (Vijaykanth), Kasi’s twin brother. We are told in a flashback by the family retainer (Chandrasekhar) that Kasi was the long-lost twin brother of Perarasu and their father, the local chieftain (Sarath Babu), was at one time the king maker of Panchalakurichi. After making Mansoor Ali Khan and Prakash Raj, MLAs he falls out with them and they murder him. Perarasu who has seen this murder now wants to take revenge. In the end Perarasu fits a bomb on a chair in a meeting on which Ilakyan sits. Kasi, desperate to save Ilakyan, goes into the room and prefers to die with Ilkyan. Perarasu feeling proud for his brother preferring to give up his life for his duty, saves both of them but is shot by Ilakyan.Kasi then shoots Ilakyan and Perarasu takes the blame before dying. The fi ends with Kasi marrying the heroine and returning to his native village.
