The film begins with two Indian agents working under Ranvir Singh (Manoj Bajpai) chasing an international arms dealer Mikhail (Prithviraj Sukumaran), who has been on the radar of several intelligence agencies, but instead he kills them both and escapes. A year later Shabana Khan (Taapsee Pannu) a college student who is also a Judo fighter is being followed by Indian agency as a potential recruit. One of Shabana’s friends, Jai (Taher Shabbir Mithaiwala) who likes Shabana, and always tries to hit on her, asks her on a date a day before his birthday, she agrees to go with him on the date and there he confesses his love for her. During the date he asks her about her past, and Shabana tells him that she had been kept in a juvenile detention institution for killing her abusive father who used to physically assault her mother. During their bike ride home Shabana is a victim of eve teasing from a group of four drunk men in a Jeep, with the exchange turning into a physical altercation resulting in Jai getting killed and the assailants running away. Soon after, Shabana receives a call from an unknown number asking if she wants to avenge her lover’s death. The unknown caller agrees to help her terminate the killer in exchange for Shabana joining a secret agency. Shabana agrees to this and accordingly receives information on the killer’s whereabouts, and the agents aid her in killing them. Shabana then goes to Goa, to the same hotel where the main culprit who killed Jai was staying. As instructed, Shabana enters his room killing him and later escapes with the help of Ajay Singh (Akshay Kumar). The unknown caller is then revealed to be agent Ranvir Singh.
Following this Shabana is recruited into the secret agency on a trial basis, wherein she is to receive extensive training in physical fitness and fighting techniques. The story then focuses on global arms dealer and supplier Mikhail. Three Indian agents then track down Tony, Mikhail’s right hand. During interrogation Tony tips them off as to the identity of a German doctor who has surgically changed Mikhail’s face. By the time the agency contacts the doctor to find out how Mikhail looks now Tony kills all three agents and escapes, revealing that he himself is Mikhail. Ranvir Singh gets the tip that Mikhail is planning another plastic surgery to change his face. This time Shabana is sent to kill Mikhail with the help of Ajay Singh and Om Prakash Shukla (Anupam Kher). Shabana enters the adjacent operation theater disguised as a patient, and after getting rid of Mikhail’s private security is about to kill Mikhail in the operating theater. To her surprise he is awake as he had refused to take general anesthesia during the operation. After quite a tussle, where Mikhail almost strangles Shabana, she finally manages to kill Mikhail and once again escape from the police with the help of Ajay.