Uday Shetty, a former Mumbai Police officer presumed dead for six years, secretly lives under the name Kennedy. During the COVID-19 pandemic, he works as a cab driver by day and as a contract killer for corrupt Police commissioner Rasheed Khan by night. Six years earlier, Rasheed and Sub-Inspector Abhijit Kaale arranged for Uday to disappear from the police force, with Uday willingly participating in the scheme. Since then, Rasheed has used him for murders, extortion, and other illegal operations. Kennedy, a psychopath who enjoys killing, keeps belongings taken from his victims as souvenirs.
On one assignment, Kennedy kills Kabir, a businessman who lives in a Mumbai apartment building. Shortly afterward, he picks up Charlie, a woman living in the same building, and she reveals that Kabir was her boyfriend and had bought her apartment. She suspects Rasheed ordered Kabir's murder because Kabir refused to cooperate with his demands. Kennedy later secretly sews a camera into his jacket and installs another in his car to record their crimes.
Rasheed is under pressure to recover the large bribe he paid to obtain his position as commissioner. With businesses struggling during the pandemic, he orders his officers to increase their extortion collections. He targets a powerful businessman known by the sobriquet "Big Papa" and plans to frighten him with a staged terrorist attack. Rasheed orders Kennedy to obtain a vehicle and rig it with explosives, intending to use the threat to extort money. Kennedy also asks Rasheed to help him locate Saleem Kattawala, a gangster with whom he has a personal feud. The plan goes wrong when the vehicle explodes at a luxury hotel. Rasheed had instructed Kennedy not to detonate the explosives, but Kennedy carries out the attack himself. Around the same time, Kennedy murders a politician and his family after the politician refuses a bribe and poses a risk to the scheme of changing the state government by a vote of no confidence. The killings create a major scandal and put Rasheed's position at risk.
After the politician's and his family's killing, Kennedy secretly breaks into his own former home. He eats some pudding from the fridge. He leaves gifts for his daughter, who claims to have eaten the pudding to her mother to cover up for him. He later follows her and texts her when she goes out with her friends, observing her from a distance. It is revealed that Kennedy has also installed cameras in the house, allowing him to watch his family while in hiding.
Kennedy's history with Saleem is gradually revealed. In 2014, Uday led a police raid on the home of actress Gunjan, who was romantically involved with Saleem. During the raid, Uday killed Gunjan's brother Chandan despite having no evidence that he knew Saleem's whereabouts. The incident damaged Uday's reputation and earned him the label of a "killer cop". Saleem retaliated by arranging the killing of Uday's young son, Adi. Uday subsequently disappeared, with the police allowing the world to believe that he was dead. His wife blamed him for their son's death and ordered him to leave.
In the present, Saleem continues to evade Uday while communicating with Rasheed. Rasheed promises Kennedy that he will help him find Saleem while manipulating both men. Charlie eventually learns that Kennedy killed Kabir. Rasheed now considers Kennedy a liability and orders one of his men, a sub-inspector and Kennedy's frequent partner in extortion collections, to deal with him.
Saleem confronts Kennedy in Kabir's empty apartment and uses Charlie as leverage. Kennedy kills Saleem and Gunjan, then gives ₹1.4 million to Charlie to give to his daughter. Suspecting that Rasheed gave Saleem his family's whereabouts, Kennedy returns to his apartment while the police raid it. He drives past and shoots Rasheed on the shoulder before escaping from the police and returning home.
Kennedy then sends an email to the government detailing his and Rasheed's crimes. He resumes texting his daughter and apologizes for not being present in her life. She correctly realizes that he is her father and that he is still alive. She repeatedly calls him, but he does not answer. As the phone continues to ring, Kennedy commits suicide by shooting himself in the mouth.
