The movie begins with an investigation of a girl who has been dead along with a small vessel. That small vessel is actually a weapon as it contains explosive chemicals (a bomb named "Ophalaska") with its changing colours.

Now comes the quarreling between two gangs, in which one gang is headed by Sarveshwaran. He lives in Kumbakonam along with his men. Another scene opens in Pollachi, where Surya is an unemployed youth. He lives in a bungalow with his joint family. He is in love with his cousin Maha. Surya sees a metal sheet written in Chinese. When he magnifies that, he sees a Chinese script along with some Tamil words.

Sarveshwaran starts talking to the portrait of his mother, who is no longer alive. He then reveals his childhood story. Sarveshwaran is the son of a handicapped woman who is a florist. He sees so many kids wearing wristwatches, buying lollipops, etc. He asks his mother for money so that he can also do the same things as what the kids do regularly. He is the student of a corporation school. He also asks his mother to get him admitted in a government school so that he can learn to speak English. His mother pleads to the principal of the government school to enroll him in that school. The principal denies it, and he accidentally pushes his mother from the balcony, resulting in her death. Sarveshwaran kills the principal the same way the principal killed Sarveshwaran's mother. Now comes the present, in which Sarveshwaran assures his mother that he will earn a lot of money. He is then revealed to be a terrorist.

Thirumalai is a cop who investigates a lorry which contains a lot of small vessels that have Ophalaskas. This lorry actually belongs to Sarveshwaran. Thirumalai gets confused to see a hospital getting converted into a lodge and injured men suddenly getting recovered. He learns that it is all because of Sarveshwaran. Selvam, one of Sarveshwaran's men, stabs Thirumalai. In spite of stabbing, he survives and calls Surya for help. Surya suddenly gets shocked upon seeing Thirumalai dead.

Surya is then revealed to be an undercover cop. He decides to foil all of Sarveshwaran's plans to destroy the whole India using a bomb called WHI (We Hate India, planned to keep bombs in 101 various places of India). Minmini, a police officer who helps Surya's for undercover plan, so she changed her name as Rekha. But she falls in love with Surya. Later he also finds the matter that Sarveshwaran has made contacts with Chinese terrorists for helping him so that India is no more. Surya, along with three undercover cops, goes to Sarveshwaran's house and kills his two men Rangarajan aka RR and Dhandapani. Sarveshwaran then kidnaps Surya's whole family, including Maha. A very few members from Surya's family are killed by Sarveshwaran. Surya keeps Selvam under his custody.

When Surya, Selvam, and the cops go to Sarveshwaran's lair, Surya is left alive while the others who came with him are killed including Selvam as Sarveshwaran finds out that he betrayed him. He saves his kidnapped family after beating Sarveshwaran's men to death. He also sees Maha being tied with a timer bomb. Surya then confronts Sarveshwaran. An ensuing fight goes between both of them. After Surya defeats Sarveshwaran, the latter falls unconscious. Surya deactivates the bomb and saves Maha. He suddenly sees Sarveshwaran missing. When he goes in search for him along with Maha, Sarveshwaran stabs Surya in his stomach. However, Surya survives the stab and shoots Sarveshwaran dead.