Didi works as a butler at Pedro's father's house. While browsing an old photograph album, he and 10-year-old Pedro find an ancient map with the route to a treasure. They decide to search for it. But the treasure carries a curse cast by the three thieves who had stolen it first, during WW2.
Deep in the Amazon rain forest, there is a lost subterranean city. The place was built by Vikings who crossed the Atlantic Ocean and ventured up the Amazon River, and shelters a mysterious treasure. In order to find the secret location, Bárbara and the children Riacho and Manhã will have to face many challenges. Vicious snakes and dangerous pendulum blades are only the beginning of our heroes' adventures.