A GCHQ translator faces a moral crisis when asked to assist in an illegal espionage operation aimed at securing UN authorization for the Iraq invasion. In January 2003, Katharine Gun, a 28-year-old translator at the Government Communications Headquarters (GCHQ), received a directive from the US National Security Agency. This directive requested her participation in a covert operation designed to manipulate United Nations approval for the impending invasion of Iraq. Horrified by the illegality and ethical implications of the request, Gun made the courageous decision to leak the information to the British press, an act that would irrevocably alter the course of her life and career. Her subsequent arrest under the Official Secrets Act transformed her into a focal point for political dissent and debate.

The book details the true story of Katharine Gun, a whistleblower whose actions in 2003 brought to light an illegal spying operation related to the Iraq War. The narrative is presented as a thriller, focusing on Gun's personal crisis and the question of where true loyalties lie. The description highlights the book's role as the definitive account of a significant whistleblower case. The upcoming major motion picture adaptation starring prominent actors suggests a strong public and critical interest in the story.