Don begins, true to its title, as the story of one of the most powerful men in the business of crime, who in spite of being one of the most wanted on the list of Interpol, remains elusive to the police. Along with the police, Don makes a few other enemies through his merciless approach to running his organization, especially when he kills one of his own men, Ramesh, when the latter decides to leave the business. This introduces Don to two new enemies, Kamini (Helen), Ramesh's fiancee, and Roma, (Zeenat Aman) Ramesh's 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, and in the process, Kamini is killed. A shattered, revenge-seeking Roma gets her hair cut short, trains in judo and karate, then enters Don's 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 realizing her true intentions. Meanwhile, after a couple of unsuccessful attempts at nabbing Don, the police finally succeed, but Don dies during the pursuit, botching Officer D'Silva's plan to reach the source of all crime—the man Don reported to—through capturing Don alive. D'Silva buries Don's body, ensuring that people believe that he may still be alive.