Orphaned at a young age, former officer with Goa Police, Arjun Vishnu Bhaagwat (Emraan Hashmi), now lives alone, though he has a sweetheart in gorgeous model, Priya (Jacqueline Fernandez).Amidst reports of police extending their search for missing prostitutes, specifically the Caucasian daughter Jyothi (Yana Gupta) of a high-profile Russian Diplomat, Arjun is hired by a gangster, Sameer (the pimp), and for a fee, must not only locate missing call-girls but also their abductor. Unable to get any clues, he than enlists the assistance of Sameer to recruit a bait, Reshma, who comes from an impoverished family, for the killer. Shortly thereafter Reshma goes missing, and Arjun loses contact with her. Guilt-ridden, he decides to use all possible resources to try and locate her before she herself becomes included in the official 'missing persons' list.Reshma was picked up by a man named Dheeraj Pandey (Prashant Narayanan). Reshma was instructed to SMS the address she was going to, but Dheeraj took away her cell phone, but treated her very gently in the beginning. Reshma is a college girl but has to sell herself to support her education as she comes from a poor family with mom & 2 younger sisters. Dheeraj is a sociopath & hates prostitutes & takes a sadistic pleasure in killing them & dumping them in a deserted well on his property. he kills Reshma & dumps her in the well too.Arjun tries his best but can't trace Reshma. He investigates further & gets the phone number from which Dheeraj books the girls for his games. He thinks the kidnapper is selling the girls in a human trafficking ring. He traces Dheeraj & gets him on the streets to elicit a confession, but the police arrest them both.In the police station Inspector Sada trusts Arjun & even Dheeraj admits to killing the prostitutes. However, Sada's senior asks Sada to keep the investigation under wraps due to the high-profile nature of the case. Sada asks Arjun to investigate and gather proof while he questions the sick mind of Dheeraj. Arjun refuses to believe that Dheeraj has killed the girls. He believes they are alive but can't convince Sada.Meanwhile in the well, Reshma regains consciousness. She is badly hurt, but alive. Arjun reaches Dheeraj's home & meets his mom & dad. They tell him that Dheeraj was married & tortured his wife & they kicked him out.Meanwhile police continue to question Dheeraj & his motives for killing the girls, but they still don't have any proof. Dheeraj is a transvestite & gets a call from a fellow transvestite political leader who says she is heading to Goa to help him out. A staff psychiatrist is brought in & Dheeraj confesses to her that he cut off his own penis to become a transvestite. The doctor surmises that Dheeraj has no respect for women, & still hungers for them. But since he can't have sex anymore, he kills them & takes sadistic pleasure in that. Reshma manages to climb out the well by next morning. Around same time the transvestite politician arrives & releases Dheeraj from police custody. Sada tells Arjun who is still gathering evidence.The politician takes Dheeraj to a temple close to his home & incidentally that's where Reshma reaches trying to escape. Dheeraj kills the politician & Reshma brutally. Arjun was told that Dheeraj was a sculptor but used to create idols of demons instead of Gods. In the temple Arjun sees an idol that he has seen in the front lawn of a house he knows. He now knows where Dheeraj is killing the girls.Meanwhile Dheeraj has lured Priya to come to that place for a photo-shoot that very night. As Arjun enters the house Dheeraj captures him & immobilizes him with strong blows to the head. He then makes him watch as he captures Priya & then tries to kill her. Arjun escapes & kills Dheeraj. Police arrives & recovers all the dead bodies from the well.