The prophet muhammad said dreams can be a kind of revelation: God speaks to us after He’s ceased speaking to us. What then is a nightmare?
It began inside Córdoba’s Great Mosque in Spain. I had a view from the ceiling, and far down below me was me, a sad and pathetic person-shaped smudge. The air tasted so old I thought I might be inhaling the exhalations of the mosque’s final congregation, from whatever day in 1236 prayers were last held there. I was unclear how I’d gotten in, and equally uncertain how I would get out. Something pulled me toward the mihrab, the niche that shows the direction in which to pray; though I drew physically closer to Mecca, I was no closer to an explanation. Instead, a terrible hollowness seemed to turn me inside out. I was dead, I suspected; this wasn’t Córdoba but some...