After a plane crash, Sai, a capuchin monkey born and raised in captivity, finds himself alone and lost in the wilderness of the Amazon jungle. Unprepared, the little monkey feels helpless with this sudden freedom. Facing a new world in which dense and luxuriant vegetation covers everything, Sai has to find his way and protect himself from the traps Nature has laid out. He finds himself face to face with all types of forest animals: jaguars, crocodiles, boas, tapirs, giant otters, and more. Sai soon understands that finding fellow capuchin monkeys and being adopted by them may be his only hope for survival.