The village priest (Bharat Bhushan) is killed by the Zamindar’s young son Tiger (who grows to be Amjad Khan) when the former discovers of the latter planning to steal the valuable jewels of the temple idol. His house is burnt down, the wife becomes blind and the son, Shankar, runs away from the law to the city and turns into a Nastik (Athiest). He becomes a petty thief and when he grows up (into Amitabh Bachchan) befriends other thieves, Balbir (Pran) and Gauri (Hema Malini). Balbir's past is also connected to Tiger (through his raped daughter).
Tiger (Amjad Khan) is now is a leading smuggler of diamonds through false eyes (he himself wears one, which Shakar had damaged in the childhood) and smuggling gold and drugs through idols and statues. Mala (Sarika) is Tiger's sister, who tries to help Shankar to find his father's killer. In the process Shankar also meets his mother and sister.
How Shankar manages to prove that Tiger killed his father and also how he can expose Tiger's illegal profile forms the climax.