The film begins with a car chase in Chicago, which leads to a scuffle between a man ostensibly named Jude Rosario and an American male known as Matthew Brody. The scuffle ends with Brody falling into the icy waters of Chicago River, and his body missing. This results in Rosario being arrested and convicted of murder.
A flashback to six months prior shows the office of the Indian RAW chief Roy, where he and his trusted men plan a daring covert operation. The man, known as Jude Rosario in the opening sequence, is shown to be Captain Daniyal Khan, a dead-end ex-soldier with a completely deadpan sense of life and death which is pulled out of oblivion and pressed into service by the spy agency to wreak vengeance on the men who planned the 26/11 Mumbai terror attacks. He agrees on the assurance that he will be reinstated in the Indian army to the same rank from which he was court-martialled, which meant regaining the respect of his estranged father, retd. Col. Usman Khan, and mentor, Dilawar Singh. His only team member, Nawaz Mistry helps him find his first target Sajid Mir at a cricket match in London. On reaffirming his identity after breaking into his apartment, Daniyal rigs up an explosion which kills Sajid, which makes the headlines explaining it was accidental, resulting in an investigation by the Pakistani ISI.
In the present day, Daniyal, aka Jude, has landed in the same jail as David Headley, his next target. He contacts Nawaz in order to acquire money to buy a battery, as a replacement for another one which holds a certain poison. The poison, (succinylcholine), is untraceable as it can kill a person when it touches the tongue, causing a heart attack. After killing Headley by plugging the poisonous battery into a showerhead he usually uses, Brody, who supposedly died upon falling in the river, is found alive, and Daniyal is released as his earlier sentence is rendered null and void. Meanwhile, ISI agents gather information about him.