An opening scene shows a famous ship, Lady in Blue, sinking into a storm, and a lone survivor, Captain Jagat Malhotra (Kabir Bedi) emerging on the sea shore.
Somewhere in the Bahamas, Aarav (Akshay Kumar) runs a successful fishing company under the title of Blue Fisheries. He shares a good bond with Sagar “Sethji” Singh (Sanjay Dutt) who works as a diver for Aarav’s fishing company. Sagar is in a relationship with Mahima “Mona” Singhania (Lara Dutta) and plans to marry her.
Meanwhile, Sagar’s younger brother Sameer “Sam” Singh (Zayed Khan) is based in Bangkok. Sam is a bike rider, and meets Nikita “Nikki” Malhotra (Katrina Kaif), a female biker who works for an underworld gangster named Gulshan Samnani (Rahul Dev). Sam is challenged by Gulshan to a bike race, and after Sam wins, he asks Nikki out for dinner. Before leaving, Gulshan asks Sam to work for him, but Sam refuses unless there’s a large sum of money involved.
During Sam’s date with Nikki, Nikki explains to Sam that the job Gulshan proposed would pay with $50,000. Gulshan hires Sam to work for him, but Sam is set up by Gulshan in failing to deliver a package costing Gulshan $50 million. Sam must either pay his money back or die. Sam does not have the money so he explains to Nikki, whom he now loves, that he is going on holiday to the Bahamas to visit his brother Sagar and doesn’t think Gulshan will find him there. Sam arrives at Aarav’s company and Sagar welcomes him happily. In the Bahamas, one ill-fated day, when sitting in a restaurant, Sam receives a call from Gulshan on Nikki’s phone, explaining that he has killed Nikki, and knows where Sam is. At the same time, as he gets out of the restaurant, Sam is confronted by Gulshan and his crew, who surround Sam, and chase him on bikes. Aarav enters and brings everyone to a halt by shooting the bike wheels, saving Sam’s life.
For now, Sam tells Aarav what he did wrong, and Aarav decides he needs to tell Sagar about the situation. When Sagar learns how much trouble Sam is in, Sam tries to convince Sagar to retrieve a famous treasure from Lady in Blue. Sagar refuses. The next day, Gulshan bombs Sagar’s home, and kidnaps Mona, with a ransom of $50 million or Sam for her return. When Sagar tells Sam and Aarav, Sam decides that they need to go and rescue Mona as they already killed Nikki and will kill Mona too. But Aarav speaks up and says they don’t know how far Gulshan is connected and they may all die, meaning the only option is to find the treasure, pay off Gulshan and use the rest of the money to live comfortably. Sagar is still hesitant and it is revealed that Sagar has a haunted and shocking past with Lady in Blue. Years ago, Sagar had to abandon his archaeologist father, Aadesh Singh, at the ship, to save his own life. However, after Aarav convinces Sagar that the treasure will save the lives of both Mona and Sam, Sagar finally agrees.
The three of them bring the treasure up and find Gulshan sitting on the top of his ship that he and his gang have steered up next to the ship belonging to Sam, Sagar, and Aarav. He tells Sam and Sagar that Aarav hired Gulshan to do all of this. Soon there is a fight between Sagar and Aarav, and Aarav jumps into the ocean after killing Gulshan. Mona, Sam, and Sagar are forced to leave him there, and Sagar agrees never to come back to the Lady in Blue, after losing two people who were close to him there – his father Aadesh and his friend Aarav.
Three months later Sagar gets a call from Aarav. Talking to them, Aarav reveals that he survived his leap into the ocean, and reveals to them that his grandfather was Captain Jagat Malhotra, the traitorous captain of the ship, Lady in Blue, who committed suicide after he was court-martialed. Aarav never admitted to Sagar who his grandfather was, because he didn’t want to dishonor his family. Aarav explains that finding the treasure of the Lady in Blue would help bring honor back to his family name, and he befriended Sagar, knowing he was the only one who could take him to the treasure. Throughout the phone call, a woman’s arm is seen around Aarav, and later, the woman asks to speak to Sam. It is revealed that the woman is Nikki, and she is Aarav’s wife. She asks Sam to forgive her for deceiving him, but it isn’t revealed if Sam said yes or no. However, while Sam answers there is a smile on Nikki’s face. The film ends with Aarav and Nikki cuddling on one of Aarav’s boats, and the end credits begin.