During a chase with the police, Billa is severely wounded after an accident and dies in front of the DSP. The DSP then secretly holds a burial of Billa. Interpol officer Gokulnath (Rahman) is assigned to work with DSP Jayaprakash to capture elusive Billa as no-one knows of Billa's death. DSP Jayaprakash keeps the death of Billa as a secret even from his fellow officers, and tracks down a look-alike called Saravana Velu (Ajith Kumar), a hotel server and small-time petty thief. He asks Velu to infiltrate Billa's gang by pretending to be Billa. In return he will make sure that the child Velu adopted, Karan, gets a proper education.