10/19/2011 08:31 am ET Updated Dec 18, 2011

Searching The Amazon For Uncontacted, Unconquered Tribes (PHOTOS, VIDEO)

After receiving his first assignment for National Geographic Magazine, an article about the efforts of a Brazilian activist named Sydney Possuelo to protect and document the uncontacted tribes of the Amazon, Scott Wallace was in such a hurry to get to the jungle that he forgot his boots. A week after receiving a phone call at his home in New York, Wallace was under the canopy headed for a patch of jungle that few Westerners had entered and fewer had left.

The Unconquered, Wallace's book about his attempt to find a tribe known only as the flecheiros or "People of the Arrow," has more in common with time travel narratives than typical travelogues: Wallace brings the reader into a world populated by peoples with no conception of the world beyond their jungle, a world that is not merely flat, but very small. This lost world is under siege by loggers, miners and poachers and Possuelo's mission to protect the tribe without destroying it by making contact, which has historically led to disease and cultural degradation, is both quixotic and understandable.

Possuelo's mandate, a sort of ethnographic Heisenberg Principle, guarantees that Wallace's fascination with the flecheiros will be unrequited and that their side of the story will remain a mystery. This proves to be the book's great virtue because it allows Wallace to rip the yarn without clear-cutting his descriptions with cultural relativism. The fleicheros are the other. Their lives are a mystery and Wallace has the good sense not to try to understand their perspective.

The appeal of the unconquered is, after all, that they -- unlike nearly everyone else -- cannot be understood as products of history, because their present and their past are both immeasurable variables.

Instead of trying to go native, Wallace turns his rigorous journalistic eye mirror-ward to document his personal journey. Instead of casting himself in the role of conquistador, he steps into a less flattering spotlight, coming across in sections as grumpy, opportunistic and out of his depth. Had he portrayed himself as capable of handling the rigors of the Amazon backcountry, the book would have completely lost its credibility. Instead, Wallace joins the tribe of jungle-besotted literary types led by Redmond O'Hanlon and David Grann and presents a credibly incredible tale about his voyage past the edge of modernity.

Wallace was kind enough to talk to HuffPost Travel about his journey and share some of his photographs.