After a treaty between India and the United Kingdom to expedite extradition is passed, Col. Viren Nanda is murdered and burnt alive by terrorist Omar Zafar in London. Omar, who is escorted by his trusted lieutenant Hamid Gul, orders a $5 million rewards for an Indian thief to steal the Koh-i-Noor diamond, so as to hold up the treaty. Later, a man named Rajveer Nanda steals it, and requests $20 million as Zafar and Gul aim to retrieve it. After a subsequent brawl with Gul’s men at a local restaurant in Shimla, Rajveer visits a restaurant where he meets an ambitious but unassuming bank receptionist, Harleen Sahni, who is waiting for her blind internet date, “Vickie Kapoor”, to show up. Rajveer assumes the date, and the pair fall in love, but he is forced to abandon her after being found by Gul’s surviving men. Harleen leaves upon learning the truth, but on her way back home, bumps again into Rajveer, who seeks her help to remove a bullet. Before leaving, he drugs her and informs her of scare tactics that some law enforcement officials will use to try and coerce her into working against him.Bang Bang! 2014. The next day, indeed as Rajveer had foretold, government agent Zorawar Kalra and his informer, Inspector Bhola, implore Harleen to travel with them to a safe place; taking note of Rajveer’s instructions, she finds a pistol and holds them at gunpoint. Rajveer soon appears and the pair escape, but meet Harleen’s manager, Karan Saxena, who Rajveer shoots in the leg.Bang Bang 2014.
Harleen, preturbed, demands that she return home, having made a huge mistake by trusting him, which leads to an argument over their loyalties, but she eventually decides to stay upon realizing that he has never allowed an innocent to be exposed to danger or to die in his presence. Rajveer later reveals during a visit to a Pizza Hut outlet that he stole the Koh-i-Noor, much to Harleen’s surprise, and the pair are immediately confronted by Zorawar and his team, who had been following the duo. Rajveer shoots Harleen with a tranquilizer dart and they escape, with Harleen later waking up at a beach shack after an unknown period on the run. After taking Rajveer’s phone to call her grandmother, which allows government officials and subsequently Gul’s men, led by his lieutenant Robert, to track them, a shootout ensues, which forces the duo to escape again after eliminating the officials and Robert’s henchmen.Bang Bang 2014.