In 1995, during the Kashmir conflict, Hilaal Meer (Narendra Jha), a doctor agrees to perform an appendicitis operation on the leader of a pro-separatist group. To avoid detection, he performs the operation at his house, much to the chagrin of his wife Ghazala (Tabu), who questions his allegiance. The next day, during a military raid, Hilaal Meer is accused of harboring terrorists. A shootout ensues at his home, during which the leader of the separatist group is killed and Hilaal is taken away for questioning.The doctor's house is bombed subsequently in order to kill any other militant hiding in there. Several days later, Hilaal and Ghazala's son, Haider (Shahid Kapoor), returns from his university to seek answers about his father's disappearance. Upon arrival, he is shocked to find his mother singing and laughing along with her brother-in-law Khurram (Kay Kay Menon). Unable to understand his mother's behavior, he begins searching for his father in various police stations and detention camps with the help of his fiancee Arshia (Shraddha Kapoor), a journalist.Depressed by the growing closeness between Ghazala and Khurram, and unable to find any leads, Haider begins to lose hope. However, Arshia encounters a stranger, Roohdar, who asks her to inform Haider that he will be able to provide information about Hilaal. Haider contacts Roohdar (Irrfan Khan), who turns out to be part of a separatist group. Roohdar then narrates the story of how he met Hilaal in one of the detention centers, where they both were tortured. Hilaal attributes his imprisonment to his brother, Khurram. Roohdaar tells Haider that he simply wanted to pass on his father's message to him: revenge for Khurram's betrayal. Thereafter, angry and swearing to avenge his father's death, Haider becomes mentally and emotionally scattered and starts to behave and act strangely. His uncle Khurram, after getting to know about the meeting of Haider and Roohdar, narrates to him that Roohdar has killed his father. He is in dual mind as to whose narration he should believe. He discloses his state of indecision to Arshia and also states that Roohdar has given him a gun to kill his uncle. Arshia unintentionally discloses to her father who informs Khurram about the gun. Khurram immediately orders his men to send Haider to a mental institution.Next morning Haider is all set to kill his uncle but cannot accomplish it because his uncle is in prayers and then is captured by Arshia's father who orders to kill him but Haider manages to escape. He contacts Roohdaar, who suggests getting trained in Pakistan to avenge for his father's death and Haider agrees. He calls his mother and informs her about it to which she asks him to meet her once before going to the other side of border. During the meet, Ghazala discloses that she had disclosed about terrorists hiding in their house out of fear to Khurram unknowing that he was an informer of the Indian army. Arshia's father traces them and is about to shoot Haider when Haider shoots him in the head and escapes.Tormented from her father's death at the hands of Haider, Arshia is deeply hurt and commits suicide. Meanwhile Ghazala finds Roohdar's number from Arshia's diary and she calls him. Haider goes to his pickup point, i.e. the graveyard where his father was buried. At the graveyard, Haider contemplates about the universal nature of mortality. Unaware of Arshia's death, on seeing her brother in the graveyard it hits his mind that the body is of Arshia. He runs towards her body where her brother sees him and informs Khurram. A fight ensues between Haider and Arshia's brother resulting in Arshia's brother's death. Khurram arrives with full force and a gunfight ensues, meanwhile Roohdaar and Ghazala also arrive at the spot, where Roohdaar drops Ghazala.A fierce exchange of bullets and bombs leaves only Haider and few men on Khurram's side alive. Just when Khurram is about to kill Haider with a rocket launcher, Ghazala requests a chance to convince Haider to surrender. She, goes to Haider, confronts him but he says that he cannot die before avenging his father's death. Ghazala tells him that revenge only results in revenge and there is no ending to this cycle, but Haider who is determined to avenge his father's death does not understand.Ghazala kisses Haider, steps outside, only to reveal that she has been wearing a suicide vest. Khurram and Haider rush towards her but she pulls the pins of the hand grenade resulting in a big blast causing the death of the rest of the men and Khurram being gravely injured with his legs being amputated. Haider goes to his mother's remains, cries a lot and goes to Khurram in order to shoot him in the eyes as per his father's wish but is reminded of his mother's words "revenge only results in revenge" and thus decides to leave Khurram. Khurram begs Haider to kill him to free him from burden of guilt and to avenge his father's death but Haider doesn't kill and leaves.