Ratnadeep (1979)

A railway TT (Girish Karnad) finds a person dead in the railway compartment whose face is similar to his. Upon searching his belongings he finds out that the deceased belong to a rich family who was returning to his home after a long time. He decides to quit the railway job and intrudes into the life of the waiting family in the guise of the deceased. All are happy to see him return home from the 'sanyas'. He finds there a most beautiful wife (Hema Malini) and a son. He finds irresistible attraction towards Hema but tells a lie to maintain distance from her that his 'guru' has taken a promise from him that he wouldn't come in contact with any women till his 'vrata' is completed. Hema eagerly waits to complete the 'vrata' and helps him in every manner, but he has different plans - to steal the money and flee.