Dr. Vaseegaran creates Chitti, a powerful robot in his own image, but it is rejected by the scientific body AIRD due to its lack of human behaviour and emotions. After a lightning strike triggers emotions in Chitti, he begins to develop human-like feelings. However, Chitti falls in love with Dr. Vaseegaran's fiancée, Sana, and turns against his creator, leading to dangerous consequences.

An ornithologist who commits suicide returns as fifth force to wreack vengeance on mankind for harming birds with mobile phone radiation. The only thing that is standing in his way is 2.0, the upgraded version of Chitti, the robot.