
Sam Cossman stood at the edge of a crater as deep as the Empire State Building is tall, wearing a custom-built suit of aluminised fibreglass cloth and fire-retardant Nomex. At the same time, two camera-mounted drones hovered above a glowing lake of lava. "It's a glimpse into the centre of the Earth," he later described the moment to National Geographic.

Some journeys take you somewhere. And some change you. A night spent on the slopes of Acatenango belongs to the latter.