Nine-year-old Sofia Diaz’s world is coming apart. So is the rickety old boat that carries her far up the Rio Negro river in Brazil. Crocodiles swim in the dark waters. Spiders scurry up the twisted tree trunks. And a crazy toucan screeches a warning. It chases Sofia and Júlia, her new friend, deep into the steamy rainforest. There they stumble upon a shocking discovery.