Krishnaswamy(Kamalhassan), a loving father of two, leads an idyllic life along the banks of the river Kaveri. He has a daughter Kaveri(Shobana) - named after the river - and a son Bharani. His wife is dead and they live with his mother-in-law. A visit by a rich friend raises visions of wealth and when a smooth-talking man Dhanush(Haneefa) tempts him to move to the city and invest in a chit fund, Krishnaswamy succumbs. But he is cheated by Dhanush and thrown in jail. There he meets Panjabakesan('Poornam' Vishwanathan) and learns that it was his daughter Yamuna who had responded to his matrimonial advertisement. Meanwhile Dhanush sends Kaveri to a bigwig who has a weakness for young girls while Bharani gets lost. After his release, Krishnaswamy tries to find his children.

Kamalhassan plays one his most down-to-earth characters here. He is an average man who is gullible, tempted by riches and almost seduced by a woman with questionable virtues. This makes the grievances he undergoes, hit closer to home. And he does undergo a lot of hardships, both physical and emotional. In jail he is taunted and beaten while after he gets out, he has to endure seeing the states his children are in. Even the scenes where he fights back are believable as the desperate attempts of a man to survive under the tough circumstances.

The intial portions, which show Kamalhassan cavorting in the waters of the river with his children, are designed to show their joy and happiness in their simple, uncomplicated lives. This increases the impact of the troubles in the second half. The visit by Kamal's foreign-returned friend is introduced cleverly as the main factor that leads Kamal to move to the city and try to become rich. The relationship between Kamal and his mother-in-law is sweet and the way he cringes when she asks his forgiveness for not thinking about his remarriage is believable.

Mahanadhi contains two main sequences of incredible emotional impact. The first is when Kamal realises that his daughter, who has come to visit him in jail, has attained maturity. This is a powerful scene that is embellished by the performances. The proclamation of Bharani that he is fourth in his own class when the grandmother uses a classroom analogy to convey the good news to Kamal makes us smile. The other sequence occurs when Kamal rescues his daughter from the red-light area in Calcutta. His silent pleas to let them leave while hugging his daughter tightly should soften even the hardest heart. Atleast, I had a lump in my throat.

The romance between Kamal and Suganya, which begins behind bars, is handled poetically. There is one beautiful scene, where Kamal imagines stepping out and playing with her and his kids before finding himself back behind bars, that illustrates his state of mind clearly. His fleeting encounters with Suganya in their house are also designed to depict their passion.

Kamal has been known to overemote but here he achieves a lot with his silent tears and expressive eyes. His performance in the two scenes I mentioned above is phenomenal and the way he breaks down after hearing his daughter utter unprintable swear words in her sleep tugs at our heart strings. Haneefa brings to life one of the most detestable villains ever to grace the silver screen. He is so sleazy that he gives dirt a bad name. It is a great performance. Sukanya and the grandmother provide adequate support with only 'Poornam' Viswanathan overacting at some places. The average soundtrack by Ilaiyaraja is elevated by Sriranga Ranga..., a beautiful song that is melodious and charms us with its simple lyrics.