The film opens with a high tech person named Johnson (Kamal Hasan) attempting to kill Chief Minister Madhava Menon (Thilakan) using a radio-operated toy car planted with a bomb, but due to unforeseen circumstances, he fails. Later, Johnson happens to watch a Mimicry show of an artist named Jayaram (Jayaram) imitating several celebrity voices. Johnson convinces Jayaram himself as a government employee and makes him to mimic the voice of Madhava Menon reading out false promises through TV and radio to the public and the image of Madhava Menon gets affected in public.

Madhava Menon appoints his friend, DIG, K. Gopalakrishna Pillai (Madhu) to investigate this case and he finds out foul play.

The flash back shows Johnson falls in love with the daughter of Madhava Menon, then a local politician and he does not like the relationship, so he destroys Johnson's family (which included his parents and four sisters), but Johnson survives. Now Johnson wants to take revenge on the politician. Johnson takes the help of mimicry artist Jayaram for this. At first Jayaram does not know Johnson's intentions, but when he knows the real reason behind it, he supports Johnson. They humiliate and assassinate the character of the Chief minister and the public is now against the Chief minister.

In the thrilling and sparking climax, Johnson forces Madhava Menon to shoot him and Johnson dies thus making the politician a murderer and destroying his political future.

• Kamal Hasan as Johnson
• Thilakan as Madhava Menon
• Madhu as DIG K. Gopalakrishna Pillai
• Urmila Matondkar as Renu
• Jayaram as Jayaram
• Sithara as Geethu
• Sabitha Anand as Jessy
• Santha Devi as Johnson's mother
• P.C.George as Police Inspector
• Jagadish
• Jagannathan as Madhava Menon's aide
• Poojappura Radhakrishnan as Security guard
• Sainuddin as Mimicry artist
• M. S. Thripunithura as Geethu's father
• Kollam Thulasi