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.