The film is a remake of the movie Witness (1985 film) (starring Harrison Ford and Kelly McGillis), with the locale shifted from Amish country to the valleys of Vadodara. It is about a young girl, Kaya (Udita Goswami) , living in the beautifully serene valley of Spiti, waiting to join a Buddhist monastery, an idea which has been fed to her all her life by her father (Mohan Agashe) and one which she has never questioned. When Lama Norbu, a senior lama from the monastery has a dream that the Buddhist teacher, the Rinpoche has been reborn as a young child, he sends Kaya to Delhi on a mission to bring him back to the monastery. Kaya goes to Delhi and manages to get the child, but just when they are about to return home, the child witnesses the murder of a Police Officer in a hotel. The investigations are taken over by another Police Officer, Shiven (John Abraham) and he prohibits Kaya (Udita Goswami) and the young boy from returning home. During this time, the boy identifies (Gulshan Grover) as the Junior Police Officer, Manali turns out to be the Commissioner of Police, and soon Shiven (John Abraham) finds himself caught in a web of intrigue and deceit where he can trust no one. He is forced to make an escape to Spiti along with Kaya and the young boy who he is now determined to protect. Shiven has however seriously been injured and upon reaching Spiti has to undergo treatment at Kaya's home. While nursing him back to health, Kaya begins to find herself attracted to Shiven, an exciting feeling she has never experienced before. Shiven too finds himself drawn to Kaya, a girl unlike any he has ever known. Kaya is caught in a dilemma for she has too long subdued her natural instincts and desires in her search for the 'ultimate truth'. A sexual attraction is one that her conditioned mind sees as a sin (paap), but one which she cannot deny. Shiven sees this dilemma and tries to show Kaya that there is a life out there which she has a full right to live. In the meantime, Kaya's father (Mohan Agashe) finds out about what has been going on under his roof and is furious with Shiven. He sees Shiven as a polluting influence upon his peaceful life, a man who has brought defiling things like pistols into their home. At this juncture, Shiven's past catches up with them and Manali's men are close on his heels. It may be notes that the story of the film is similar to the Malayalam movie Yodha starring Mohanlal, which has developed the close bond between the boy and the hero. Paap is basically a strongly written love story which conveniently uses the backdrop of the mountains and the exotic locations to breathtaking effect. The film features the hit song Garaj Baras by Ali Azmat, the lead vocalist of the Pakistani band Junoon.