Don

Don begins, true to its title, as the story of one of the most powerful men in the business of crime. In spite of being on Interpols Most Wanted list, Don (Amitabh Bachchan) remains elusive to the police. Besides the police, Don makes a few other enemies through his merciless approach to running his organization. Notably, Don kills one of his own men, Ramesh, when Ramesh decides to leave the business. This introduces Don to two new enemies, Kamini (Helen), Rameshs fiancee, and Roma, (Zeenat Aman) Rameshs sister.

When Kamini seduces Don and attempts to have the police arrest him, her plan backfires as Don outsmarts her and the police in his escape. In the process, Kamini is killed. A shattered, revenge-seeking Roma gets her hair cut short, trains in judo and karate, then enters Dons gang after deceiving them into thinking that she too is on the wrong side of the law. Don is impressed with her fighting skills and allows her to work for him without suspecting any ulterior motive.After years of unsuccessful attempts at nabbing Don, the police finally succeed.

Unfortunately, Don dies in the heat of the chase, botching Officer DSilvas plan to reach the source of all crime the man Don reported to through capturing Don alive. DSilva buries Dons body, ensuring that people believe he may still be alive. As luck would have it, DSilva remembers his chance encounter with Vijay (Amitabh Bachchan), a simpleton trying to survive in the hustle and bustle of Bombay in order to support two small foster children, who is an exact lookalike of Don. DSilva hatches a plan to transform Vijay into Don so he can arrest the rest of the gang.Around the time Vijay returns to Dons gang as Don under the guise of amnesia, Jasjit (Pran), just released from jail, begins his mission of revenge against DSilva and his search for his children Deepu and Muni, who had been saved and taken care of by Vijay.

Vijay manages to replace the red diary with a blank one, and tells his gang that he is going to take revenge on the DSP, but is actually going there to give him the red diary. Roma goes after him, but Vijay survives the attack and he tries to explain to her that he is not Don, but Vijay. She refuses to believe him at first but DSilva intervenes and tells her that the man she is trying to kill is indeed Vijay.Meanwhile, as Vijay learns more and more about Don through his discovery of his diary and Romas help, he announces to his colleagues that his memory has returned. Celebrations ensue as Don announces his return to the world, but things take a drastic turn when the police raid the celebrations, acting upon Vijays information, but Vijays only witness to his true identity, DSilva, dies in the crossfire.

Tangled in a web of confusion where the police refuse to believe that he is Vijay while his underworld gang realize that he is indeed not Don, Vijay incites the ire of both the police and Dons right-hand man, Narang. To add to Vijays woes, the diary that Vijay had handed over to DSilva his last hope of proving his innocence is stolen by Jasjit in an attempt to track down his lost children, without realizing that Vijay is the one man who can reunite them. Vijay escapes the clutches of the police and the underworld with Romas help and returns to his old self though he struggles to prove his identity and innocence. After Vijay fights against Vardans men Roma ends up getting the diary. One of the gangsters snatches it from her and burns it.

The ending reveals that the burnt diary was, in fact, the fake diary, and that Vijay had the real one in order to trick Vardan. Vijay gives the proof to the police and all charges are put against him. Vardan is arrested and Vijay returns to his old life, along with Roma, Jasjit, and Jasjits children.