Amarnath (Dilip Kumar), a well-known lawyer, is known for his sense of justice.
One day, he meets Soniya (Nimmi), a milkwoman. She is awed by him and he finds her interesting. Amar's father wants him to get married and sends him Anju's (Madhubala) photograph. Anju has graduated from a foreign University and believes in justice and aiding the poor. Both she and Amar take a liking to each other and they are soon engaged.
One night, after attending a local fair, Soniya is attacked by the local ruffian Shankar (Jayant) who wants to possess her at any cost. In a bid to escape him Soniya runs heedlessly into Amar's house as a thunderstorm begins. In the lonely house, Amar ends up raping Soniya. Amar's conscience torments him as he tries to hide his misdeed and proceed with his engagement to Anju.
Anju senses something is amiss, but cannot fathom what it is. Meanwhile, it is revealed that Soniya is pregnant. She refuses to name the father of her child and is cast out by the villagers as a fallen woman. Shankar manages to figure out who the father of Soniya's child is and wants to avenge her. He ends up dying by his own hands.
Amar is accused of murdering him and the truth regarding him and Soniya comes out. The villagers eventually want to lynch Soniya. Anju supports and protects her. In the end, she ensures that Amar officially marries Soniya and leaves the village once her duty is done.
Synopsis cource credit: https://en.wikipedia.org/wiki/Amar_(1954_film)