This emotionally charged crime drama follows the fluctuating fortunes in the life of David. After getting released from prison after 22 long years he visits his dear friend Velapan. A flashback shows that David and Rosy were married and had a happy life. David is politically active in the grassroots movement and introduces his wife and newborn son to the leader of his party, the powerful politician Suryaprakasam, whom David trusted and had a high regard. The child is named James with Suryaprakasam's blessings.
However, Suryaprakasam is an evil man and was smitten by Rosy, when he saw her. He concocts a plan; he organizes a political protest with David as the leader, knowing David will get arrested; thereby allowing him access to Rosy.
Suryaprakasam succeeds in his plan. Rosy then comes to him for help in getting David released, and Suryaprakasam rapes her violently with his henchmen's help. Shamed and humiliated, Rosy then commits suicide and leaves her husband a handwritten note with the details.
Velapan bails out David. David who is proud to have gone to jail for Suryaprakasam's protest, comes home singing his praises until he sees Rosy hanging dead and reads her note. Upset, David confronts Suryaprakasam at his birthday function and makes a scene. Inspector Viswanathan and Dr. Unnikrishnan pretend to help David, but are actually Suryaprakasam's friends and they destroy Rosy's note, thereby the entire evidence of the crime.
The trio then frame David for Rosy's murder and easily win the case and David gets sentenced to life imprisonment for killing his wife. He leaves his only son with his close friend Velappan, who promises to raise David's son as a hardened thug, who will help David avenge Rosy's humiliation and death, and David's wrongful imprisonment.
Upon release from prison, David sees that Velapan is a changed man, no longer engages in questionable activities, educated David's son and raised him in a righteous way. David's son James is now called "Shankar" and is a well-respected and courageous police inspector. David is upset at this news, knows he cannot count on Velapan and his own son, and vows his revenge against the trio who framed him by himself, without anyone's help.
David comes to a church to confess his plan; he says to the priest that, he would kill 3 people, without naming them. The priest informs this to the police, who try in vain to capture David. David starts his revenge by killing the now Superintendent Viswanathan methodically and escapes by fooling Inspector Shankar. He then kills Dr. Unnikrishnan despite strong police protection and escapes.
David is supported by Sharadha, the love of Shankar. The climax shows David killing his last target, Suryaprakasam, and how Shankar has to fulfill his duty of shooting his father.