The film focuses on a very conservative Namboodiri family in a very regressive social milieu. Ishti centres around two main characters, a 70-year-old Ramavikraman Namboodiri, who is a Vedic scholar who preserves the fire from a Somayagam to light his funeral pyre, and Sreedevi, his young, third wife. Sreedevi stands up against orthodoxy. She manages to inspire her husband’s son from another marriage to read and write. The conflict between these characters and those who revolve around their lives is what the film is generally about. It then also becomes a strong comment on the attempt to balance worldly desires and the rigidity of caste and tradition.