Karuthamma (Sheela) is the daughter of an ambitious Hindu fisherman, Chembankunju (Kottarakkara Sreedharan Nair). She is in love with a young Muslim fish trader, Pareekutty (Madhu). Chembankunju’s only aim in life is to own a boat and net. Pareekutty finances Chembankunju to realise this dream. This is on a condition that the hauled by the boat will be sold only to him. Karuthamma’s mother Chakki (Adoor Bhavani) comes to know about the love affair of her daughter with Pareekutty, who belongs to another religion and reminds her daughter about the life they lead within the boundaries of strict social tradition and warns her to keep away from such a relationship. The fisherfolks believe that a fisherwoman has to lead a life within the boundaries of strict social traditions and an affair or marriage with a person of another religion will subject the entire community to the wrath of the sea.
Karuthamma sacrifices her love for Pareekutty and marries Palani (Sathyan), an orphan discovered by Chembankunju in the course of one of his fishing expeditions. Following the marriage, Karuthamma accompanies her husband to his village, despite her mother’s sudden illness and her father’s requests to stay. In his fury, Chembankunju disowns her. On acquiring a boat and a net and subsequently adding one more, Chembankunju becomes more greedy and heartless. With his dishonesty, he drives Pareekutty to bankruptcy. After the death of his wife, Chembankunju marries Pappikunju (C. R. Rajakumari), the widow of the man from whom he had bought his first boat. Panchami (Lata), Chembankunju’s younger daughter, leaves home to join Karuthama, on arrival of her step mother. Chembankunju’s savings is manipulated by his second wife. The setbacks in life turns Chembankunju mad.
Meanwhile, Karuthamma has endeavoured to be a good wife and mother. But scandal about her old love for Pareekutty spreads in the village. Palani s friends ostracize him and refuse to take him fishing with them. By a stroke of fate, Karuthamma and Pareekutty meet one night and their old love is awakened. Palani, at sea alone and baiting a shark, is caught in a huge whirlpool and is swallowed by the sea. Next morning, Karuthamma and Parekutty, are also found dead hand in hand, washed ashore. At a distance, there lies a baited dead shark. —Wikipedia