Inside the illicit trade in West Africa’s oldest artworks

Outside it has become night. In front of the windows of one of Abuja’s grandest hotels, the pool shines turquoise blue. Finally, the phone rings. It is the hotel’s front desk, announcing a guest. The man who comes into the room, hours late for the scheduled appointment, is named Umaru Potiskum. He is an art dealer. He’s wearing a dark blue dashiki and is full of self-confidence, but is also a little suspicious. His is, after all, an underground, illegal business. “Here I have met many customers,” he says — buyers from Belgium, France, Spain, England and Germany. He shows us what he’s selling, carefully unwrapping two delicate terracotta statues from a piece of cloth. The eyes gazing out from...