Set in Calcutta during the 1950s Mahanagar explores the evolving independence of middle-class women of the city. Arati (Madhabi Mukherjee), a home maker, takes up a job as a door-to-door saleswoman to meet the increasing financial pressure on her family. Despite familial adversity and societal obstacles the initially hesitant and nervous Arati soon begins to prosper in her field and gradually starts to enjoy her new-found financial and psychological independence. Her initially supportive husband, Subrata (Anil Chatterjee), who now starts to feel insecure decides to ask Arati to quit but is finally forced to let her continue to work once he loses his job. Arati now becomes the sole breadwinner of the family and also befriends an English-speaking, Anglo-Indian (representative of the legacy of the British Raj) colleague Edith (Vicky Redwood), a move which raises suspicion and increases conflict within her family.