A journey into the cobalt belt of the southeastern Democratic Republic of Congo, where excitement about rising global demand for electric cars has helped draw tens of thousands of people into informal underground mining. Cobalt is an essential ingredient in the lithium-ion batteries that power electric cars, and most of the world’s supply is found in a small region of southeastern Congo – which is one of the world’s poorest countries despite its vast mineral wealth. After reports of dangerous conditions and child labour in the Congolese cobalt industry, it is fighting to preserve its place in the green technology supply chain.