As a fundamental particle, the electron is central to an understanding of the nature of matter. All of chemistry is dependent on the interaction of electrons on the outside of atoms. But the electron has also become increasingly central to our lives, first through the deployment of electricity and then as the essential driving force of electronics, with all its quantum subtlety. We spend our entire lives now bathed in the electron's output, whether we are simply turning on a light, looking at a phone or working on a computer. And with the move away from fossil fuels, the electron becomes ever more our most important servant. In this fascinating book, Brian Clegg reveals a remarkable story of scientific wonder and innovation, and paints a compelling picture of one of the most essential components of life itself.