It began with a tantalizing, anonymous email: "I am a senior member of the intelligence community."

What followed was the most spectacular intelligence breach ever, brought about by one extraordinary man. Edward Snowden was a 29-year-old computer genius working for the National Security Agency when he shocked the world by exposing the near-universal mass surveillance programs of the United States government. His whistleblowing has shaken the leaders of nations worldwide, and generated a passionate public debate on the dangers of global monitoring and the threat to individual privacy.

In a tour de force of investigative journalism that reads like a spy novel, award-winning Guardian reporter Luke Harding tells Snowden's astonishing story - from the day he left his glamorous girlfriend in Honolulu carrying a hard drive full of secrets, to the weeks of his secret-spilling in Hong Kong, to his battle for asylum and his exile in Moscow. For the first time, Harding brings together the many sources and strands of the story - touching on everything from concerns about domestic spying to the complicity of the tech sector - while also placing us in the room with Edward Snowden himself. The result is a gripping insider narrative - and a necessary and timely account of what is at stake for all of us in the new digital age.