A ruthless gangster worms his way into the affections of a timber merchant. Using lies, deceit and murder he plots to usurp the place of the merchant's son, steal his inheritance and his girl.
Randhir and Ranvir Verma are twins. Randhir is straightforward, while Ranvir is a petty criminal. These petty thefts add up, and soon the police arrest Ranvir, and he is sentenced to prison. In prison, Ranvir incurs the wrath of a gangster, Tony, and is killed. Randhir undertakes to find the killer, and gets himself arrested, and imprisoned to get to see who the killer is. After getting out from prison, Randhir plans to avenge his brother's death, without knowing that he himself could endanger his very life, as well the life of his girlfriend, Mala. The song "Chandni chand se hoti hai, sitaron se nahin, pyar bhi ek se hota hai hazaron se nahin..." is still popular.
Mamta lives a poor lifestyle with her husband, Dinu, and two sons, Mohan, and Sohan. When Ram Lal, the wealthy Zamindar, Kanta Prasad Gupta's Munim, comes to them to take Sohan to Mrs. Sharda Gupta for ten days, they reluctantly permit him to do so. After 10 days, Gupta himself approaches them and begs them to let his wife keep Sohan for life. They tearfully agree. Then Mohan gets into trouble, and Dinu scolds him, only to find out that Mohan has run away from home. A search proves futile, and the couple continue to live a childless life. Now 17 years later, Mamta is seriously ill, and asks Dinu to bring Sohan back. Dinu goes to the Zamindar's house where he meets a young man who identifies himself as the real son, Suraj, and informs him that Sohan has been asked to leave. A devastated Dinu loses his memory and roams listlessly on the streets of Calcutta, unable to remember anything.
Murder interferes with a couple's wedding night when the groom dies mysteriously. Eventually, the widow, Sumitri, finds love again, but faces obstacles from society and, possibly, the killer.
