Ajith Kumar, Laila, Vivek, Prakash Raj
Subramania Siva (Ajith) is in jail, awaiting the death sentence for killing corrupt and evil members of the police force who had killed his father and sister. SP of Police, Nethiadi Nandakumar (Prakash Raj) is an honest, fearless and upright police officer who has been given the mission to flush out the terrorist outfit behind the Coimbatore blasts. He decides to employ unconventional methods to fulfill his mission and engages Siva to assist him, renaming him Paramasivan, and giving him a single-point agenda – trace out and erase the persons responsible for the Coimbatore blasts. Unaware to Paramasivam, Nandakumar intends on killing him after the mission is completed.
The fly in the ointment is played by Nair (Jayaram), a CBI officer, who is out to trace Paramasivan and stop his unlawful activities. His assistant, SI Agniputran is played by Vivek, who provides lighter moments. How Paramasivan finishes the villains and finishes his job forms the rest of the story. Paramasivan comes to know of Nandakumar's idea to kill him after the mission during the last few scenes where the CBI officer Nair intervenes and eventually the hero is forgiven and starts a new life with his lover Laila.