Omar Zafar (played by Danny Denzongpa) is Interpol's one of the top most wanted criminal who is imprisoned in London's special detention zone. While, Deputy Police Officer Viren Nanda (played by Jimmy Shergill) is handling a special case to filter the menaces trying to harm the internal security of the country. And there happens a confrontation between Viren Nanda and Omar Zafar and his goons' assassinate Viren and he easily finds his way out from the detention zone. It is then that Omar Zafar proposes to pay a hefty amount to the one who steals the ancient historically significant Kohinoor Diamond from London's high security tower. It is then that Rajveer Nanda (played by Hrithik Roshan) executes a perfectly planned diamond heist with Hamid Gul\'s (played by Javed Jaffrey) confederation without a single flaw or any hard evidence. Rajveer contravenes to accept the reward in exchange of the Kohinoor diamond as he develops suspicion. He also comes across Harleen Sahni (played by Katrina Kaif) who is a receptionist working in the Bank of Shimla. She is on her pursuit to find her perfect match with the help of online dating portal. She has been living her small yet happy life in India post her parents' demise after which she was brought back by her grandmother to take care of her. She is a smart yet whimsical girl waiting for her perfect match. On the day of the date, Harleen misconceives Rajveer to be Vicky and approaches Rajveer which leaves him astonished by her grace and he reverts back to her cute salutation. Harleen blindly falls for Rajveer and gets carried away by his charm. However, she discovers Rajveer's intensions, but before she can step back, she falls prey to his subterfuge. They set themselves on a transit mission and changes countries between day and night to avoid getting caught. They both join hands on a mission to protect the historically significant Kohinoor diamond from Hamid Gul's garrison who is Omar Zafar (Danny Denzongpa)'s partner in crime. How are they going to protect the Kohinoor diamond and what are their next set of plans will unfold as a perfect high octane action film.