Preston Goodman, a Mormon missionary on his way to begin his assignment in Boliva, is involved in a crash of a small plane in the deepest part of the Amazon Basin. The crash was caused by the botched attempt by one of a trio attempting to steal money from their employer.
The premature explosion wiped away the front of the plane, killing the pilot, the highjacker and another male passenger. Only one of the trio of highjackers survives. The beautiful and worldly Francine alone knows the full story of the highjacking and the treasure she is hiding. She uses her beauty and wiles to attain her goal despite the seriousness of the groups' situation.
Needing an ally, Francine chooses the less serious of the two Mormon missionaries who also survived the crash. Playing on his naive desire to be of help, she convinces Preston to help her in her private plan to abscond with the treasure and elude her employers. For a time, it appears that her plans will be thwarted by the seriousness of the situation facing the six surviving travelers.
Francine's beauty attracts the attention of a wily native, Chukka, while she and Preston are out on an exploration excursion. With Chukka's help, Francine and Preston are able to reach a native camp on the mighty Rio Negro. After Chukka and his friends go back to the plane to rescue the others, Francine and Preston take off in a stolen motor canoe in accordance with Francine's nefarious plan to abscond with the treasure.
Before they can reach their goal, Preston is left for dead by Francine after they are accosted by a native who deems the pair to be his enemy. Attacking Preston from the rear, the frightened native hits him on the head causing a horrible wound. Believing that Preston is dead or dying, Francine exhibits her unusual ability to survive by persuading the native to help her in her plan of escape.
Believing that he is a Godman from Guyana, two hunters from a camp upriver, find Preston and take him back to their camp. Through the unnatural skills of a near-insane Shaman, Preston's life is preserved, but he awakes from a deep coma without a memory.
Thought of as a disturbed person because of his lost memory, he is
protected by the natives and permitted to live with them for four years. His life is miserable, but his desire to learn who he is
remains strong enabling him to survive the rigors of the native life.
He is dubbed the SILENT GIANT by his benefactors and jailers.
Learning their ways, his skill and stature become known by other
tribes in the Basin. His being unable to speak the native tongue
adds to the mystery surrounding the man from nowhere.
The legend of the SILENT GIANT reaches the ears of Randall Kent in San Francisco. Kent was aboard the plane when it crashed years before. The terrible nightmare of being marooned in one of the most remote spots in the world and his subsequently marrying the other missionary's sister, changed his life forever and he felt a keen sense of obligation to find Francine and Preston. With his ample resources, Kent sets out on an expedition to find his long lost fellow passenger.
Before Kent can find him, Preston is discovered by a representative of a trading company from Manaus, Brazil. Because of his lack of memory, he is given the name, Charles Poole, by his
All is strange to the newly named Charles, but he eagerly accepts the menial employment as a warehouse laborer offered to him by his benefactor, Peter Forrester. Through his native talents
and his unremembered upbringing, he stands out among the workers at the warehouse. Though cordial, he remains somewhat of a recluse
because of the fact that his memory extends only to the time he opened his eyes in the native camp.