 Two convicts and small time crooks (Amitabh and Dharmendra) are picked by Thakur (Sanjeev Kumar), a former police officer, to seek vengeance on the dangerous bandit Gabbar Singh (Amjad Khan) because he killed all of Thakur s family (except a daughter-in-law) and maimed Thakur for life.This was a result of an earlier incident in which Thakur -- acting as a police officer -- had captured Gabbar and helped in his conviction in the court. Gabbar managed to escape and wreaked havoc in Thakur s life. Now Thakur seeks the help of these two crooks to get Gabbar. The ensuing action makes for one of the most exciting Indian movies made to date.