Vijayapuri, a beautiful hillside hamlet appears serene and restful to a casual passerby. But the happenings there are far from tranquil. Dacoities, burglaries and even kidnappings seem to be commonplace occurrences. One established perpetrator of at least some of the crimes is Kaathavarayan, his secret accomplices being some well-known public figures like the rich young wastrel Veerarajan and the Kuttipatti Zamindar.

The other dacoit is apparently the mysterious Malaikkallan. Legends are galore on his fabulous wealth, awe-inspiring exploits, contempt for the unprincipled rich, concern for the poor and needy indeed he seems to be running a veritable empire in some hidden hillock; no one has actually seen him.

There is also the wealthy merchant Abdul Raheem, who seems to disappear at regular intervals from Vijayapuri, claiming business calls at far-off places. In this hotbed of intrigue and suspicion blooms an innocent rose Poonkothai, daughter of the upright Sokkesa Mudaliar. Veerarajan is the cousin of Poonkothai and desires to marry her, but his evil reputation ensures the impossibility of such an alliance. Having lost her mother at an early age, Poonkothai is brought up by her widowed aunt Kamakshi Ammal. Kamakshi Ammal's only son Kumaraveeran went missing many years back.

Faced by stringent public criticism for their failure to tackle the audacious crimes, Sub-Inspector Arumugam arrives in Vijayapuram. But his assistant Constable Karuppiah is a bungling coward and is more a hindrance than a help in his investigations. It is at this juncture that one night when Mudaliar is away, Poonkothai is kidnapped. The happenings of that eerie night keep the village tongues wagging for many days thereafter. Two sidekicks of Kathavarayan are found tied and hanging upside down, and a piece of Poonkothai's jewellery is recovered from them. Kamakshi Ammal is found tied-up and unconscious, and a mysterious errand-boy hands over to the attending doctor a forest herb that revives her at once. Poonkothai is said to be in the custody of Malaikkallan, who has cleverly waylaid Kathavarayan's men and taken away Poonkothai. Kathavarayan faces the ire and ridicule of Veerarajan at the behest of whom he had engineered Poonkothai's kidnapping. Goaded by this humiliation, he now sends his men far and wide in search of Poonkothai. Meanwhile, Poonkothai is safe in the magnificent hideout of Malaikkallan, perceiving his genuine concern for the downtrodden and the reverence with which he is held by his people, her contempt and mistrust turn gradually into admiration and leads to love.

Several confounding twists and turns later the truant pieces of the puzzle fall in place. Kathavarayan and Veerarajan get their well-deserved comeuppance. Malaikkallan and Abdul Raheem both turn out to be the same person who is the long-missing Kumaraveeran. All is well that ends with the happy marriage of Poonkothai and Kumaraveeran.