Kabir Malhotra (Anupam Kher) is a billionaire tycoon who invites four people to his island home in Greece, by sending a different letter to each. The four people, who have never met before, are:
Neil Menon (Abhishek Bachchan), a drug lord in Turkey. He has financial problems with mob bosses that Kabir offers to help with.
Vikram Kapoor (Jimmy Shergill), an actor with drug and career problems. Kabir writes to him that he wants to finance the biggest film ever made, and offers Vikram a role in it.
OP Ramsay (Boman Irani), a political leader in Thailand. His campaign is under threat of scandal, and Kabir offers to provide new funding to him.
Tisha Khanna (Shahana Goswami), a crime journalist in the United Kingdom who is looking for her big break. Kabir writes to her saying that he has a huge story and invites her to cover it.
The four guests arrive on the island, where they are greeted by Kabir's personal assistant Samara Shroff (Gauhar Khan) who takes them into a dining room that is being secretly filmed. There, Kabir reveals that he has invited them because of their link to his daughter, Maya (Sarah-Jane Dias), whom Kabir has spent years trying to find.
Maya was trafficked as a child by OP Ramsay, as an adult brought into the crime world by Neil Menon, and in the end killed in a car accident by Vikram Kapoor. Kabir has gathered evidence against the three of them and invited the International Vigilance Squad (IVS) to the island to arrest them.
Tisha Khanna, the only innocent one of the group, was invited because, previously unknown to her, she is Maya's fraternal twin sister and Kabir's only remaining biological child. Tisha rejects Kabir's attempts to forge a relationship with her, claiming that she doesn't want his fortune.
Unable to escape the island, the group await the arrival of the IVS. In the morning, they hear what sounds like a gunshot from Kabir's room. They find Kabir Malhotra dead in his study, seemingly having committed suicide with a gun.
The IVS, led by Sia Agnihotri (Kangana Ranaut), arrive on the island. She watches the video of the previous night's speech by Kabir, but as they are unable mmouse clicksto find the evidence that Kabir claimed to have, they let the guests go. The case is declared a suicide, but Sia puts all four guests under surveillance.
Through flashback, it is revealed that Neil was in love with Maya, who saved his life during a shootout at his casino. In the present day, Neil takes revenge on OP Ramsay and Vikram for what they did to her, tricking them into giving public confessions of their crimes. Vikram commits suicide, and OP Ramsay dies of a heart attack (his medication being stolen by Neil). Sia, who has been monitoring Vikram and OP Ramsay, knows that Neil is responsible.
It is revealed that Neil is also on the IVS. His real name is Arjun Singhania, and has been in deep cover for many years. He, too, doesn't believe that Kabir committed suicide, and works together with Sia to find the true culprit. Neil noticed that Kabir was left-handed, yet the gun that killed him was in his right hand.
Tisha, as Kabir Malhotra's only child, is to inherit Kabir's fortune, but Neil and Sia receive news that Tisha attempted suicide. Wen Tisha wakes up, she tells them that it wasn't suicide, but someone attacked her in her house. Meanwhile, Neil has found that Kabir has a brother, Iqbal, who is next in line to inherit his fortune. Sia and Neil travel to the missionary where Iqbal lives, but they find him too ill to speak to them. A nurse tells them that Iqbal had a daughter who died, but Neil notices that there are letters sent to him dated after her supposed to death, so she must still be alive.
Neil and Sia travel back to the island, where they confront the late Kabir's personal assistant, Samara. It is revealed that Samara is Iqbal's daughter and Kabir's biological niece, though Kabir never knew. Neil realised that there was foul play when, at the missionary, he saw a picture of Kabir and Iqbal when they were children, and they were identical twins, so the man in the missionary couldn't have been Kabir's brother. Iqbal reveals himself, explaining that he's been working with Samara to get Kabir's fortune. Tisha was a surprise they hadn't anticipated, so they had to take her out of the picture. They used Kabir's three guilty guests to deflect suspicion from Samara, predicting correctly that the police would suspect one of the guests as responsible for Kabir's murder.
Iqbal attempts to kill Neil and Sia, but Neil resists, which results in Iqbal being killed and Samara arrested.
