Surjit Singh (Rajesh Khanna) earns a living driving a truck. He is a rash driver and more than usually also driving while drunk. One night he stops at the prostitute Chamelibai's (Bindu), spends the night with her, and gets up late the next morning. He rushes out and drives at breakneck speed in thick fog to make up for lost time while again drinking. He inevitably ends up running over and killing a farmer named Ram Din. But despite the opportunity to hit and run, he decides to stay and face the consequences. He is arrested by the police, charged, and brought before the courts.Surjit acknowledges his guilt to the Judge (Rehman) who in-turn knows that he should send Surjit to prison for two years. But moved by the plight of Ram Din's family (which include his widow Malti (Meena Kumari); his sister Kamla (Kumari Naaz); two young sons; a crippled father Ganga Din (Nana Palsikar), and his blind mother (Leela Mishra)), and his inherent belief that imprisonment does not serve the good of the victim or the perpetrator, the Judge resolves to try a novel experiment of forcing Surjit to live with Ram Din's family and looking after their financial needs. A horrified Surjit attempts in vain to convince the Judge to change his ruling. He is transported to his new "prison" under police protection, where he is met by hostile villagers. Ram Din's family detest his presence, and call him "Dushman" (The enemy). Surjit attempts to escape on the first night, but is apprehended and brought back to serve his time.He gradually comes to terms with the twist of fate that has forced him to become a subsistence farmer and live under the ever unforgiving eyes of Ram Din's family. Over time he starts sincerely working for the family and its interests. He meets Phoolmati Mumtaz, a happy-go-lucky girl who operates a small bi-scope machine to entertain the village kids. They take an instant liking to each other, which blossoms into love. He also finds friends amongst the previously hostile vi
