'The War Within' is the story of Hassan, a Pakistani engineering student in Paris who is apprehended by western intelligence services for suspected terrorist activities. After his interrogation, Hassan undergoes a radical transformation and embarks upon a terrorist mission, surreptitiously entering the United States to join a cell based in New York City. After meticulous planning for an event of maximum devastation, all the members of the cell are arrested, except for Hussan and one other. With no alternative and nowhere else to turn, Hassan must rely on the hospitality of his former best friend Sayeed, who is living the American dream with his family in New Jersey. Deciding to go forward and carry out his own attack, Hassan takes advantage of Sayeed's generosity while plotting his strategy and amassing materials to create explosives. Eventually, Hassan's skewed religious fervor clashes with his feelings for Sayeed and his family, especially Sayeed's sister Duri.