The gripping true story of Katharine Gun, whose job at GCHQ involves routine handling of classified information. Until one day on the eve of the Iraq war she receives a memo that reveals a dubious intelligence operation. A woman of principles she feels she can’t stand by and watch the world be rushed into an illegal war. She leaks the memo to the press, exposing a vast political conspiracy, and putting herself and her family directly in harm's way. Anchored by a fiery central performance from Kiera Knightley, this pacy, powerful, engaging thriller is a pertinent reminder that our world needs everyone to act according to their principles.