Based on world-shaking true events, Keira Knightley stars in the untold story of British intelligence specialist Katharine Gun. One day in 2003, and the lead up to the Iraq War, Gun receives a memo with a shocking directive: collect blackmail worthy information on UN council members to force the vote for the invasion of Iraq. Unable to stand by and watch the world be rushed into an illegal war, Gun makes the gut-wrenching decision to defy her government and leak the memo to the press. So begins an explosive chain of events that will ignite an international firestorm, expose a vast political conspiracy, and put Gun and her family directly in harm's way.