Sandesham movie is about the family of a retired station master which consists of his wife, 3 sons and 2 daughters. Raghavan Nair (Thilakan) who retires as station master from a small town in Tamil Nadu and returns home to his family in Kerala. Having spent almost 40 years in government service he’s looking for a peaceful and relaxed ever after. Back home his two sons Prabhakaran (Sreenivasan) and Prakash (Jayaram) are arch rivals - being party workers owing loyalty to two opposing political parties. While Prabhakaran is a local party worker for the Republican Party of India (Communist leanings), Prakash is a proactive member of the Indian National Socialist Party (something like the Congress). Prabhakaran and Prakash squabble over everything from domestic political issues to international policies in Nicaragua and Poland and bring their ideologically diverse political opinions to the dinner table.
At first their father is impressed with their passionate debates and knowledge of world affairs… but slowly he realizes that his sons do not take any responsibilities at home and are willingly exploited by their local leaders for the party’s benefit. Neither of them contribute to the family’s income and take their parents for granted. Things come to a head when Raghavan is arrested for unknowingly giving shelter to a wanted naxalite and both his sons don’t turn up to help him. Raghavan then takes it upon himself to bring his irresponsible sons back on track.