Bolai Mali's wife died at the time of delivery of her daughter. Bolai left everything only to bring up his daughter Munni. His daughter won the best prize for an essay on Mothers' Day Mothers Day. Highlighting that her father played the dual role of mother and father. She handed over the prize to his to her father.

Nupur Chatterji has fled from her home in Delhi, resisting an arranged marriage with a man she dislikes. She comes to Calcutta to her college friend, but as her home is not safe she takes shelter in the house of one Anjan Mukherjee. Though initially annoyed, Anjan, a bachelor and a music director cum singer from Lucknow, comes to empathise with Nupur. In this situation enters the great detective Bhanu with Jahar, his assistant, for by now Dr. Digambar Chatterji has declared a prize money of ten thousand rupees for finding his missing daughter.