Sridevi plays a schoolteacher named Devki Sabharwal who is popular with her students . Her step daughter Arya ( Pakistani actress Sajal Ali ) however refuses to accept her as her mom and prefers to call her as ma'am , the excuse for this being that Devki is also her teacher in school . Devki tries the best to build a mother daughter relationship with Arya but gets rebuffed every time . But Devki is still protective towards Arya and smashes the cellphone of the guy ( Mohit ) who sends porn videos to Arya to the ground . On Valentine's day Arya goes to a party where Mohit and his buddy Charles again try to get Arya to dance with them . Angered by her rejection , the two combine with a criminal named Jagan ( played by Abhimayu Singh ) to rape and injure Arya and throw her in a ditch . Hell breaks lose in Devki's and her husband anand's ( played by Pakistani actor Adnan Siddiqui ) life . The court case against the rape accused totally fails to get them convicted , and Arya grows even more distant from Devki because the rapists had taunted her asking to call her mom again to save her when they raped her . Devki decides to take the law in her hands and ready to help her is a quirky detective named DK , played by who else but Nawazuddin Siddiqui . The manner in which Devki takes revenge on all the rapists is quite interesting to watch , and keeps you really hooked on to seeing the movie . But the last on her list ( Jagan ) is too tough a cookie to crumble . Will he be able to wreak havoc in the Sabharwal family's life again ? And police officer Mathew who is handling the whole case ( played by Akshay Khanna ) , is onto her track . Will he arrest her for taking the law in her own hands or help her ? Nawazuddin Siddiqui predictably gets the best lines to mouth in the movie , and as usual he mouths them with aplomb in his cameo . But best acting is by Sridevi , who is simply great in expressing grief over her daughter's rape or in expressing anguish over her inability to get justice for her in court . However her south Indian accent does stand out while mouthing her dialogues . Photography of the film is simply great when it moves into the snowcapped mountains towards the climax . Never has mountains and snow been photographed more beautifully . Music is decent . Colours of the film are okay . Some of the scenes of violence and of Arya in hospital are not easy to watch . Verdict---Good. Three and a half stars out of five .