Gradually, TAINA becomes a guardian of the forest and does everything to prevent the smuggling of animals. She manages to save a young monkey that escapes the grasp of SHOBA, a wild animal smuggler who, with his gang, has received an order to capture a female and cub of the Lagothrix species to be used in research abroad. TAINA and her grandfather name the young monkey CATU (Beautiful) and it becomes her inseparable friend after the death of old TIGE. Protected by a stone Muiraquitã amulet, left to her by her grandfather, TAINA continues to defend the forest. Chased by Shoba and his gang, TAINA meets RUDI, a solitary hydroplane pilot who lives on a floating port on the banks of the Rio Negro.

Rudi takes TAINA to a small settlement where biologist ISABEL lives with her son JONINHO. He does not want to accompany his mother on her scientific research in the jungle, far from the delights of malls and cheeseburgers, which he does not forget. Joninho and TAINA do not get along, as Joninho scorns TAINA and her Indian habits.

TAINA then decides to leave the settlement, but Joninho had already been planning to run away in order to play a trick on his mother; he follows TAINA and then has to learn how to survive in the forest.
Feeling they have been conned by Shoba, who sent them the wrong monkey, one of a different species, Miss MEG and her assistant SMITH arrive in Manaus. They discover that ISABEL is doing similar research to theirs and order Shoba to find Joninho so they can get the diskette with the research data the boy’s mother has spent years gathering.

TAINA, Joninho and Catú are now chased by Shoba and his bungling assistants, BOCA and BIRIBA, who will do anything to catch them. Only TAINA’s courage and the help of her grandfather’s spirit saves them.