Writer: Girish Kohli
Cast: Sridevi as Devki Sabarwal: Arya’s step-mother and biology teacher
Nawazuddin Siddiqui as Daya Shankar “DK” Kapoor: a detective
Akshaye Khanna as Central Bureau of Investigation CBI Officer Matthew Francis
Adnan Siddiqui as Anand Sabarwal: Arya’s Father
Sajal Ali as Arya Sabarwal: Devki’s step-daughter
Abhimanyu Singh as Jagan
Pitobash as Baburam
Vikas Verma as Charles Diwan
Ivan Rodrigues as the School Principal
Adarsh Gourav as Mohit, Arya’s classmate
Biology teacher Devki is vivacious and popular among her students. In a class, a student, Mohit sends Devki’s stepdaughter, Arya an offensive video and Devki throws his phone out of the window. At home, despite Devki’s persistent and warm approach toward her, Arya remains frosty and distant, rebuffing her attempts to build a relationship. Arya is invited to a Valentine’s Day party at a farmhouse; Devki permits this with great hesitation. Arya rejects Mohit and his hotshot buddy Charles at the party. Angered by this very public rejection, Charles, Mohit, Jagan and the watchman Babu attack Arya when she leaves the party. They brutally rape her and dump her in a drain along the side of a road, leaving her for dead after half-strangling her. She is found barely alive and brought to the hospital, where she undergoes various operations to save her. Devki and her husband Anand are shattered. Arya recovers and releases a statement naming her attackers.
Inspector Matthew quickly rounds up the attackers. However, the case falls apart when Arya was found to be drinking, thus building the argument that her memory is unreliable. The body samples were recovered very late and were too weak to match the attackers. The judge acquits the four attackers due to lack of evidence. Her lawyer suggests appealing to a higher court but Devki has lost faith. Arya, still in shock and broken by the court verdict, tears away from Devki. In sorrow, Devki realizes she has probably lost Arya forever.
Devki recalls the somewhat shady detective, DK, whom she’d met on the night Arya was raped. A father of a daughter himself, he understands her pain and agrees to help her as Devki wants to avenge Arya.
The watchman is first. Devki seeks the help of her former students – transgender people who understand her plight. They seduce the watchman and drug him. He awakes four days later, still drunk, and finds, to his horror, that he has been castrated and remembers nothing. The hotshot Charles is next. Devki breaks into his home and mixes crushed apple seeds – a source of cyanide – into his fitness powder. Charles is paralyzed. When Mohit visits Charles at the hospital, Devki, tipped off by DK, plants apple seeds and other evidence at Mohit’s home. Inspector Matthew quickly arrests Mohit; Charles will die soon and Mohit will be the murderer. As Devki takes down each of Arya’s attackers, their situations make it on the news, which Arya follows with surprise. She believes it may be her father, and she is deeply grateful to him. Matthew also suspects the father but, although he has him tailed, cannot catch him out. Then he finds Devki’s glasses in Mohit’s apartment and starts suspecting her.
Matthew confronts Devki but there is no evidence. He warns her that the fourth man, Jagan, is a hard criminal: going after him is dangerous for her family. Jagan visits Charles and learns that it is “the mom” (Devki) who is retaliating. He goes after DK and discovers that Devki is on a holiday at a snow cottage in Kufri. He kills DK and goes after Devki. Matthew discovers a hidden camera in DK’s sunglasses and hurries to save Devki.
Jagan cuts power at the cottage and shoots Anand. There is a scuffle and Arya runs out into the snow. Jagan pursues her and Devki tries to save her. As Jagan is about to kill Devki, Matthew intercepts and tackles Jagan. There is a standoff: Devki points a gun at Jagan and Matthew attempts to talk her down by telling her that Anand is alive and in the hospital and if she shoots him, she’ll go to jail. Arya, in the bushes, overhears Jagan when he angrily relates how Devki finished off the other attackers. Devki knows if Jagan is left alive he will come after her again. At this point, Matthew hands her his gun and urges her to kill him. Devki hesitates but when an overwhelmed Arya acknowledges Devki as ‘Mom’ for the first time, Devki shoots Jagan dead. Arya hugs her.