ZANZIBAR, TanzaniaAs Said poured oil onto the top of the taxi driver’s head, I kept expecting it to run down his neck and onto his shirt. It never did. No matter how much oil Said poured, it seemed to disappear into the man’s scalp. Once the bottle was empty, Said took the plastic cap and started to press it where the oil had vanished, making circular marks. Sucking in a deep breath, he began chanting a melodic Arabic verse. The cadence of his words and the rhythm of circle-making became hypnotically synchronized. Several minutes in, the taxi driver started to shake.  Said’s eyes sparkled. Breaking briefly from his verse, he said, “You see now, the jinni is coming out.”

I was sitting