Dr. Vasi (Rajnikanth) invents a super-powered robot, Chitti, in his own image. The scientific body, AIRD, that must approve the robot, declines it based on its not having emotions and the ability to make rational judgment. A sudden flash of lightning evokes emotions in the robot, and Chitti is seemingly ready for integration into the human world. Then, Chitti falls in love with Dr. Vasi’s fiancee Sana (Aishwarya Rai) and turns on his creator.

Its 2035 A.D., where robots are everyday objects and are programmed to live alongside humans. Detective Del Spooner is called out to investigate the apparent suicide of the scientist behind these robots, Dr. Alfred Lanning. Spooner suspects that the death might not be a suicide, but the result of one of the robots. All robots are programmed by three laws, but Spooner starts to wonder if a robot can in fact feel emotions, and possibly murder. But if Spooners suspicions are true, he is going to have a hard time convincing everyone.