A global intelligence competition means that espionage is spreading into our workplaces and our living rooms. Adversaries like China, Iran and Russia have realised that everyday people are targets because we work at companies that supply our industrial base or vote for our leaders. As a result, they target all of us - stealing our financial data and medical records, eavesdropping on our conversations and using platforms like TikTok or Hollywood movies to influence our opinions and votes.The Fourth Intelligence Revolution reveals how the swashbuckling adventures of World War II, the spy-versus-spy confrontations of the Cold War, and the "find-fix-and-finish" counterterrorism missions after 9/11 have given way to the most dangerous period of espionage yet. This eye-opening account exposes how intelligence now permeates every corner of society, from economic espionage and biological intelligence to information operations targeting children through online education - even extending to reconnaissance on the far side of the moon. At the same time, it reveals how AI and autonomous technologies are revolutionising the field, driving us toward a future where most intelligence will be created by machines, for machines.The Fourth Intelligence Revolution serves as both a warning and call to action, highlighting the dangers of these emerging threats and the risks of mismanaging this revolution. Yet, it also offers hope, demonstrating how we can seize this pivotal moment to reinvent espionage in a way that is more ethical, transparent and democratised. In its boldest argument, the book suggests that we are all, in essence, becoming intelligence officers and that citizens have both the power and responsibility to reclaim some intelligence missions to safeguard and strengthen our democracy.