The film begins with Karan Anand, a man waking up in decrepit old house in an unknown area. He gets a call from his wife inquiring where he is. Unaware of his location, he searches the house for a cigarette. He accidentally opens a room and finds it filled with Russian soldiers. One of the them starts chasing him and opens fire at him. He gets shot in the leg and jumps into a bathtub he finds in the snow. The man wakes up in a bathtub. He is revealed to be K (John Abraham), a wealthy businessman in his 30s. He is confident, narcissistic and very arrogant, and also completely addicted to smoking. He smokes almost constantly – at work, at home, even in the bath and while having sex. His friends and family beg him to quit, but to no avail. K’s friend Abbas (Ranvir Shorey) and his doctor (Kiku Sharda), offer to set up an appointment at a rehabilitation centre called ‘Prayogshaala’ (‘The Laboratory’), which they claim will surely rid K of his habit. K finally relents after his wife Anjali (Ayesha Takia) leaves him, unable to take the strain K’s smoking addiction places on their relationship.
K decides to check out Prayogshaala, and meets Shri Shri Prakash Guru Ghantal Baba Bengali Sealdahwale (Paresh Rawal). The centre operates behind the front of another business, ‘Kalkatta Karpets’. K finds the building to be unconventional and confusing, similar to a Labyrinth. The method Prayogshaala uses to cure their patients of their addiction is based on fear and psychological manipulation. Each time a patient gives in to their vice, Baba makes sure that something shocking happens to them.
Offense #1 : Almost killing a loved one, by keeping him/her in a chamber full of cigarette smoke the person has smoked in his entire life, for a duration of 5 minutes.
Offense #2 : Losing a finger.
Offense #3 : Death of a loved one.
Offense #4 : Taking the soul of the person from his body, although this offense is described very loosely.
K initially refuses to sign the contract and pay the fee of ₹ 21,11,111 for his treatment but is forced to do so by Baba and his disciples. Baba then tells K that he is free to leave, but he must abide by the rules or he will suffer the consequences. K witnesses other members of the group as they try to quit smoking. Many end up losing fingers as they cannot resist the urge to smoke. K tries to keep to the terms but fails twice and is punished. He is now very conscious about the third time.
After some time, K meets an old friend, Alex, who is now a Cuban cigar seller. At an event, K is forced to place a cigar in his mouth, in order to appease his friend. Seconds later, he receives a phone call from the police, who inform him that his wife is missing and possibly dead. He calls Baba and is told that for smoking, his wife will be killed, as per the rules. He protests that he did not actually smoke and Baba apologizes for the mistake, but says it is too late. K asks Baba to tell the police about this, but the line goes dead and the phone number is non-existent on dialling. K’s protests are ignored and the police believe that he is delusional. Trying to prove his story, he seeks out Abbas, who had lost a finger at the rehabilitation centre, only to find that the man has all fingers intact. Mocking him, the police force K to smoke. Shortly afterwards, K gets a phone call that his brother committed suicide due to his smoking habit. K raves angrily at the police and is thrown in the jail.
K is eventually bailed out. Soon, he learns that Baba permits sins and vices to be done during a period known as ‘Zero Minute’. He attends an event, where he sees Baba, but is unable to reach him. K decides to light a cigarette. Suddenly, K wakes up in a Russian army base, with a call from his wife. She asks him why he believes she is dead. K is confused, but escapes from the base by jumping into water and ends up in a ragged room, from which he sees himself staring out from a hospital room. He also sees his wife and Baba. He calls out but no one can hear him, and he is told that it is because his body no longer hears his inner soul. The final punishment is complete.
In a series of haphazard events, the twisted path of K’s soul is shown, until it finally reaches his body once again. K wakes up in his home to find his wife sleeping near him. He also discovers that he is missing two fingers. Later, K is seen recommending the “Prayogshala” centre to a friend.
