The movie begins with Sethurama Iyer Mammooty visiting Isow Alex (Kalabhavan Mani), a convicted serial killer who is awaiting his execution. Alex was arrested and convicted for the cold-blooded murder of seven people in two different families. Alex, who had been living a wild life then, had committed the crime high on narcotic drugs. The murder case was left to the CBI for investigation and an able officer, played by Siddique, nabbed Alex in no time. Alex is now a new man, mainly due to the influence of a priest (Gopi), who requests Iyer to visit Alex.
What Alex tells Iyer is startling; he didn't commit one of the seven murders he was convicted for. The murder was that of Manikkunju, a businessman. Manikkunju, along with his daughter-in-law Mosi, was murdered at his house. Alex tells this all the same confessing that he murdered Mosi. The possibility of another killer involved is very remote and Alex is a serial killer who thoroughly denied any hand in the murders when he was arrested, but yet Iyer decides to reopen the case and investigate. He faces many odds; to prove Alex right would be proving his own bureau wrong and to prove Alex wrong would be wasting time and money.
It was later revealed that Mani had an affair with Mosi and they were caught in a compromising position by Manikkunju. Since Mani was married he did not wish his affair to be leaked and hence he murdered Manikkunju.