Seetha, a young woman, is travelling via train with her nephew Raju to an estate to attend her job interview as a nanny to the estate merchant Manohar's daughter. Her co-passenger tries to rape her, but suddenly he is shot dead. Seetha sees the murderer and clearly remembers his face, and reports the murder to Moorthy, a police inspector. Then she is appointed for the nanny position, and she and Manohar's daughter Shoba grow fond of each other.

Manohar, who is extremely fond of his daughter, returns from his journey. Seetha meets him, only to realise that he is the murderer she saw on the train. Manohar threatens Seetha not to tell anyone and makes sure to prevent her from leaving his estate as she is keen on reporting him to the police.

Seetha tries many times to escape but is always caught. She does not even tell the police when she meets them, as Manohar threatens to kill Raju if she did. Later, Seetha somehow sees beneath the rough, mean Manohar and grows fond of him but is confused why such a nice man is acting so arrogantly.

In flashbacks, Manohar and a woman named Kumudha fell in love and married; shortly thereafter, their daughter, Shoba, was born. However, Kumudha's uncle Chandru, who was eager to marry Kumudha but who was sent to jail by Manohar as he tried to kill him, was released from jail after completing his term. When Manohar was out of the house, Chandru raped Kumudha; due to this, she commits suicide, and Manohar wants to die with her, but she makes him vow that he will get revenge on Chandru for separating them and to take care of Shoba.

Manohar reveals that the man he killed on the train was Chandru. Seetha now understands his acts and vows not to tell anyone. Moorthy's colleague is curious about Seetha; she said that she remembered the face and was eager to find the murderer, but now she had told him she has forgotten the face, hence he suspects Seetha to be the murderer, and Moorthy agrees with his belief. On Shoba's birthday, Manohar is to announce that he is to hand over all his wealth to Seetha and surrender to the police, but before this, the police arrive and try to arrest Seetha. Manohar saves her by confessing to the murder, leading to his arrest.

A few years later, Manohar is released and reunites with Seetha and Shoba.