In the beginning, there was nothing; ‘there was darkness on the face of the void’. Then came a burst of energy: ‘let there be light and there was light’, though from where it came I don’t know. What we do know is what happened next: this energy coagulated into matter and its mysterious opposite, antimatter, in perfect counterbalance. Ordinary matter is the familiar stuff, which makes air, rocks, and living things. But matter’s faithful opposite, identical in all respects except that deep inside its atoms everything is back to front, is unfamiliar. This is antimatter—the antithesis to matter.