On my first morning in the Mainland Hotel, a run-down place with falling ceiling tiles and broken locks, I awoke to a din, and I realized it was simply the city: the clatter of the 17 million people of Lagos. It was louder than any metropolis I had ever heard. My windows were closed, but it sounded as if they were wide open. For the next few days, I wandered around the city not quite sure where to begin. I went to bookstores and took motorcycle taxis and asked people I met, friends of friends, but without much insight or luck.

Eventually I found my way to Jankara Market, a collection of cramped stands under a patchwork of corrugated-tin sheets that protect the proffered branches, leaves, seeds, shells, skins, bones, skulls, and dead lizards and toads from the elements. All these items are held to contain properties that heal, help, or harm, depending on what one needs them to do. The market is better known for the even darker things one can buy. At Jankara, one can buy juju: magic. On my first trip to Jankara, to look around, I met a woman who loved me, she said, and wanted to marry me. When I told her I was already married, she threatened to bind me to her magically with two wooden figures so that I would not sleep at night until I saw her. But she said it with a glint in her eye, so I didn’t worry.

A few days later, I returned to Jankara to ask her some questions. As soon as I walked into the dark, covered grounds of the market, she saw me.

“Ah,” she said. “You have come back!”

“Yes,” I said.

“Sit here,” she said, and pointed to a bench. She sat down across from me. “What did you bring me?”

I showed her some fruit I had brought.

“Ah, very nice,” she said and started to eat, even though it was daytime in the middle of Ramadan and she was Muslim. “How is your wife?”

“She is good.”

“And what about your other wife?”

“Who is that?”

“‘Who is that?’” she said in mock surprise. “I think you know who that is. That is me.”

“That is nice,” I said. “But in America it’s not possible.”

A man came up to her and handed her a crumpled piece of paper with a list of ingredients on it. She peered at the list, then got up and went around collecting sticks and leaves and seeds and plants. She chopped them all up and put them in a bag. While she was doing this, the man sat next to me on a bench.

“Is that for you?” I asked.

“Yes,” he said. “It makes you very strong.”

Then another man came up and put in his order. It was something for the appendix, he said. When he was gone, the woman sat down next to me.

“I have a question,” I said.

“Yes.”

“In my country, we don’t have juju.”

“Yes.”

“But I was reading in the paper about penis snatchers—”

“Ah,” she interrupted me. “Don’t listen to them. That is not true. If I touch your thing like this”—and here she touched my leg—“is your penis gone?”

“No,” I said, uneasily. “But what if I come to you and ask you for protection? Can you do it?”

“Yes, I can.”

“How much?”

“One thousand naira. Two thousand. Even up from there.” This was a large sum by Nigerian standards—more than $15.

“Do you have many people come and ask for this?”

“Yes,” she said in a low voice.

She looked around.

“Many.”