 In the 70s, the ambitious and brilliant Daniel Ellsberg (James Spader) aims to work in the Defense Department of the USA. His ambition destroys his marriage and he goes to Vietnam to fight. He meets Patricia Marx (Claire Forlani), the daughter of a wealthy manufacturer of toys, and they have a brief affair. Once back in the USA, he works as analyst for the Rand Corporation and he finds secret Defense Department documents showing that the American population was being deceived along four successive governments about the Vietnam War. With the support of Patricia and his close friend Anthony Russo (Paul Giamatti), he decides to disclose the documents to the American people, being accused of treason by the government of Richard Nixon.