This fast-paced investigative thriller opens when Harikrishnan (Mammootty), a famous movie director, is found dead at his house one morning. DySP Achuthankutty (Mohanlal) is assigned to probe the death. Anilkumar (Rahman), his younger brother, is in love with Shilpa, who is in shock after receiving the news of the murder. Achuthan kutty's investigation leads to three different female suspects. The rest of the plot centers around the probe by Achuthan Kutty.
Achuthankutty uncovers a key clue in the form of a female footwear from the house where Harikrishnan was murdered and gathers other evidences leading to a woman being the killer. He figures out from Harikrishnan's family and friends that he, though being a talented director and writer, does not have a good character. He is almost sure that Harikrishnan was murdered by some woman who suffered abuse at his hands.
Another clue is a photograph of a beautiful woman, Parvathi's (Unni Mary) and leads it to a middle aged woman leading the life of a Saint in a Hindu Ashramam. She is now known as Bhagini Sevamayi. He arrests the lady because she refuses to answer his questions. Shilpa tries to talk to Achuthankutty because the arrested lady is a close friend of her mother's and her loving aunt.
He is told that there was a close relationship between Harikrishnan and Shilpa. He is not able to figure out if Harikrishnan has a paternal feeling or romantic feeling towards her. Shilpa breaks down and tells him that Harikrishnan was just impressed by her literary skills and nature and was like an uncle and guide for her, but somehow her mother could not digest their bond. Achuthankutty then questions Shilpa's mother and from her he uncovers Harikrishnan's past.
They were all lecturers in their youth and Harikrishnan was trying to woo her innocent and good natured friend. She tried to stand between them, and ends up getting raped by Harikrishnan. Her dejected friend eventually took up the life of a saint. Shilpa is actually Harikrishnan's illicit child and she was unhappy with their relationship because she suspected Harikrishnan would abuse his own daughter.
She accepts that she had planned to kill Harikrishnan, but found him dead when she arrived at his house. Achuthankutty meanwhile could not fit all evidences together and talks to his brother that he is going to question Shilpa and her mother again, with more brutal methods. Anil tries to persuade his brother out of it, but couldn't succeed. Anil finally confesses that he was in love with Shilpa was jealous of Harikrishnan and killed him. He then commits suicide, leaving a bewildered Achuthankutty staring at his corpse. Achuthankutty sets Anil's suicide note on fire.