Raja Kumar Bahadur alias Gyan Shankar Rai (Raaj Kumar) has been a total abstainer all his life, never touching a drop of alcohol, and keeping away from women and all known vices all his life. Then one day he sees a young woman named Saudamani (Hema Malini), and instantly falls in love with her. He finds out about her background, and virtually buys her, and brings her to his palatial home. This is when he takes to drinking, and wooing her, and renaming her Madhuri, but refrains from marrying her.
Years later, he sees another beautiful woman, about half his age, named Sumita (Raakhee), meets with her parents, pays off their debts, and marries her in the bargain. He brings Sumita home, but makes it clear that Madhuri?s word is law here. Then Kumar finds out that Sumita had a childhood sweetheart in Shekhar (Vinod Mehra), who has now returned from abroad. Kumar meets with Shekhar and finds out that both still have feelings for each other. An insecure and jealous Kumar now schemes a plot against them on the historical grounds of Fatehpur Sikri It is here Kumar?s plot unfolds to entrap the young lovers, thus giving the title "Lal Patthar".