Ganga Singh lives in Gangotri with her brother, Karam. One day she comes to the assistance of a young man, Narendra Sahay, who has come with a group of Calcutta-based college students to study the source of the holy river Ganga, and to get some holy water for his wheelchair-bound paternal grandmother. Both are attracted to each other, and on the next Puran Mashi get married, and spend the night together. Narendra leaves, but promises Ganga that he will be back soon. Months go by, but he does not return. She gives birth to a son, and as soon as she is able to, she starts her journey to Alipor, Calcutta, to confront Narendra and ensure a better future for their son. At Rishikesh she is exploited by two women and a man from whom she escapes and takes shelter in a crematorium. Then at Banaras, she is molested by a Pandit, rescued by the police and given a ticket to Calcutta. When she alights en route to get water for her baby, the train leaves, and she falls into the clutches of Manilal who feigns blindness and lures her to a brothel near Banaras, where she is forced to stay so that she can provide for her son. It is here that she is introduced to powerful politician, Bhagwat Choudhary, who pays a hefty sum and asks Manilal to bring Ganga to Calcutta where he intends to keep her as his and Jeeva Sahay's mistress. What Ganga does not know is that Bhagwat's daughter, Radha, is Narendra's bride-to-be; that Jeeva is none other than Narendra's father, and that soon she will be asked to dance at his wedding reception.