In 2002, Scott Wallace, right, embarked on a three-month trek to locate the Amazon’s isolated, indigenous “People of the Arrow.”

In 2008, photographs of red-dyed, “lost” Amazonian tribesmen firing arrows at a plane overhead stunned people around the world. When National Geographic journalist Scott Wallace saw the photos, he had a more personal response: “It’s blown my story!”

Wallace had just finished writing a book proposal for what would become “The Unconquered: In Search of the Amazon’s Last Uncontacted Tribes.” But rather than steal his thunder, the photos “electrified the atmosphere,” Wallace says: Five publishers bid on his book.

In 2002, Wallace — who will discuss his book Thursday — trekked for three months through the Amazon to locate (but not make contact with) the mysterious “People of the Arrow.” The 34-member team was led by a swashbuckling Brazilian activist for Indian rights, Sydney Possuelo, who wanted to document indigenous tribes without disturbing their lives or bringing disease upon their settlements. “The Unconquered” tells the cinematic, Conradian tale of exploring one of Earth’s last uncharted territories.

Wallace’s original article appeared in National Geographic in 2003, but publishers weren’t immediately sold on turning it into a book. “Then I started lecturing about this journey and showing my photographs, and the results were overwhelmingly positive,” Wallace says.

In the years between the article and the book, Wallace made other trips to the Amazon and filed reports from rough places such as Baghdad and the Himalayas. But his venture with Possuelo “was the hardest [reporting job], from the standpoint of duration, deprivation, isolation, discomfort, hunger.”

It’s easy to picture “The Unconquered” being made into a movie. “I have some friends in the business who have directed the book into the hands of a few high-profile directors,” Wallace says. “But I don’t have any commitments.”

That doesn’t mean he hasn’t thought about who might play him in a film. “I think it would be extremely flattering if someone like Clive Owen played me — or Brad Pitt,” he says. “And I think Javier Bardem would make a great Possuelo.”

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