Oru Mukham Pala Mukham (1983)

Raveendran Thampi is unable to fathom why his widowed mother, Subhadramma Thankachi is hostile to him. This leads him to alcohol addiction, and the car he was driving while drunk meets with a road accident which kills Madhavan, a worker in a factory owned by his family. Sentenced to prison, he meets Krishnan, a fellow prisoner, who tells him the terrible truth - that he is actually the grandson of Rajasekharan Thampi, the patriarch of the family and heir to the family fortune. Subhadramma, sister of the patriarch, had exchanged Raveendran and her own son Sukumaran Thampi so that her son inherits the fortune. Raveendran is shattered by this news and vows revenge on the woman who had wrecked his family and had caused the deaths of both his parents and grandfather.