What does "cyber" even mean? And where does the idea come from? We live in an age increasingly defined by technology. But as we check our emails, board a plane, or read about the latest Russian hack, we rarely ask how the ideas that shaped our modern world originated. Thomas Rid's revelatory history of cybernetics pulls together disparate threads in the history of technology: from the invention of radar and pilotless flying bombs in World War Two, to artificial intelligence, virtual reality, cryptocurrencies, and present day fears about cyber security.