Endhiran, Rajni plays dual roles. One is a scientist and the other is a Robot. Scientist Rajni creates a Robot with artificial intelligence – like that of sixth sense in humans – to help human beings and to the development of the country.
But its silicon heart falls in love with Aishwarya Rai. Writes romantic poems and the Robot behave just like a human being. Knowing about the extra ordinary intelligence of the Robot the villains try to get control of the Robot.
Scientist Rajni fights to save the Robot falling into the hand of the enemies and destroys the evil forces using the Robot itself.