Abdur Rehman Khan (Balraj Sahni), a middle-aged dry fruit seller from Kabul (Afghanistan), comes to Calcutta to hawk his merchandise and befriends a small Bengali girl called Mini the daughter of Rabindranath Tagore who reminds him of his own daughter Amina back in Afghanistan. He puts up at a boarding house along with his countrymen. Since he is short of money he decides to sell his goods on credit for increasing his business.
Later, when he goes to collect his money, one of his customers abuses him and in the fight that ensues Rehman warns that he will not tolerate abuse and stabs the man when he does not stop the abuse. In the court Rehman's lawyer tries to obfuscate the facts but in his characteristic and simple fashion Rehman states the truth in a matter of fact way. The judge, pleased with Rehman's honesty, gives him 10 years' rigorous imprisonment instead of the death sentence.
On the day of his release, he goes to meet Mini but discovers that she has grown up into a woman and is about to get married. Mini does not recognize Rehman, he realises that his own daughter must have forgotten him too. Mini's father gives Rehman the money for travelling back to Afghanistan out of Mini's wedding budget to which Mini agrees; she also sends a gift for Rehman's daughter. The film ends with Rehman travelling back to his homeland.