"The chains are usually held by the same hand," Ben says, but quietly and he stops talking before they reach the crowds. He steers Ibani in front of him, a hand on her shoulder protectively, as he navigates the crowd, occasionally with a smile and a nod to some acquaintance or other.

He exchanges a couple of wupiupi coins for a pitifully small amount of water shared between two gourds, and hands one to her. "You can drink some when we get out of the city," he says, "but hold on to it until then."