 Mohan is a young man who lives with his widowed mother, is in love with a young woman named Shyama, and both would like to get married. Unfortunately, before that could happen, Shyama is shot dead, the police get involved, an eye-witness named Bindiya names Mohan as the killer, as such Mohan is arrested, tried in Court, found guilty and sentenced to be hanged. The only one who believes in Mohan s innocence is his mother, Gangadevi. She advertises in the newspapers offering a reward of Rs.10,000/- to whoever can prove her son innocent, asking readers to direct their responses to Post Box 999. No one ever responds, until after 5 years when a Reporter, Vikas, of "Prakash" publications comes across the ad and decides to prove Mohan innocent. Assisting him are Gangadevi and a young woman named Nilima, eventually both Nilima and Vikas fall in love. Their investigation take them to a variety of people, including Banarsilal, Bindiya who witnessed the killing, and a killer named Shamsher Singh, who abducts Nilima. Now Vikas has only one day to prove Mohan s innocence, and he must use it to either do that or save Nilima from Shamsher s clutches.