 Nirmal Verma (Manoj Kumar) and Karuna (Vyjayanthimala) are attracted to each other, while Nirmal is touring that part of the country. They get very intimate, and Nirmal promises to return, and leaves his address with her. To her misfortune, Karuna misplaces his address. After about five years Karuna and Nirmal meet again, and Nirmal immediately introduces her to his brother (Ashok Kumar), who is a doctor, and his bhabhi Janki (Nirupa Roy). They are married with great pomp and ceremony. The doctor, and Nirmal find out that whenever the others are out of the house, Karuna secretly leaves the house and goes to an unknown location, the whereabouts and who she meets is something she is not willing to disclose to anyone including Nirmal.