But even with the immune suppressant, Daniel’s symptoms never fully went away. Not only were the red scales near his scalp, on his forearms, and on his legs embarrassing, they were extremely painful and itchy. And his joints always felt stiff and cold, like he was coming in from a long day of skiing.

It was then that Daniel broadened his research to include the growing list of autoimmune diseases: rheumatoid arthritis, psoriasis, multiple sclerosis, lupus, Crohn’s disease, Sjogren’s syndrome, celiac disease, Hashimoto’s thyroiditis, type 1 diabetes, pernicious anemia, and alopecia areata, among countless others.

More and more, researchers were connecting a person’s microbiome—all the bacteria, fungi, protozoa, and viruses that live on and inside the human body—to autoimmune disease. Specifically, the gut microbiome. An estimated 70 to 80 percent of immune cells are in the intestines, making the gut the linchpin of the immune system.

During his research, Daniel read a paper called “Super Microbiome of Tribal Amerindians,” which detailed how scientists found that the most diverse collection of human microbes belonged to a tribe of indigenous people in the secluded jungles of southern Ecuador.

Researchers collected skin, oral, and fecal samples from the tribe. The samples, which contained bacterial DNA, were compared to samples from American subjects and several other first world nations. The results showed that the tribe’s people had substantially greater microbial diversity than did industrialized populations.

Another article reported that after testing the DNA of seventeen indigenous populations in the Amazon rainforest, the prevalence of autoimmune disease was a scant 3 percent, compared to 8 percent in the industrialized world.

Daniel theorized that one of the billions of undiscovered microbes buried in the soil of the Amazon could be responsible for the indigenous populations’ relative immunity to autoimmune disease. He spent a year learning Spanish, then told his father and godfather that he was taking a year off to study soil samples in the Amazon jungle.

After clicking through the rest of his emails, Daniel jumped on Facebook. He had two messages. One was from a spammer, but the second was from an old college classmate, Jordan Mae. The message read, “You’re not going to believe this. I stumbled on these images at work yesterday.”

Three images were attached. As predicted, Daniel didn’t believe it.

The first was a wide shot of jungle canopy, all 3,200 pixels a shade of green. The second image was an enlargement, and Daniel could see the details of each of the trees and a small break in the canopy. But it was the third image that was pure magic: a close up of a golden jaguar faceup in the dirt.

Under the three images was Mae’s final message: “I think it’s the same statue from the book!”