Even today there remain tribes in the far reaches of the Amazon rainforest that have avoided contact with modern civilization. Deliberately hiding from the outside world, they are the unconquered, the last survivors of an ancient culture that predates the arrival of Columbus. Journalist Scott Wallace chronicles an expedition into the Amazon's uncharted depths, discovering the rainforest's secrets while moving ever closer to a possible encounter with one such tribe of seldom-glimpsed warriors known to repulse all intruders with showers of deadly arrows. On assignment for National Geographic, Wallace joins Brazilian explorer Sydney Possuelo at the head of a 34-man team that ventures deep into the unknown in search of the tribe. Possuelo's mission is to protect the Arrow People, but the information he needs in order to do so can only be gleaned by entering a world of permanent twilight beneath the forest canopy. -- from publisher description.