Without even a single map, our driver speeds us off into the heart of South Sudan. It hasn’t rained since anyone can remember, lakes have evaporated and the ground is cracked like an old man’s skin. I spot something moving.

‘Slow down, what’s that?’, I shout excitedly, thinking maybe we’ll find a leopard after all. But no, it’s a Mundari girl! With a baby strapped to her waist, she takes a last glance at us and hurries off into the bush – the baby bobbing up and down on her back as they disappear into the distance. ‘Don’t worry’, says Donald, ‘She’s just never seen a car before. We’re the first outsiders to have ever come here.’