An idea that could help bring internet access to remote parts of the world takes Jack and his genius siblings deep into the Amazon rainforest in the final thrill-packed adventure in the New York Times bestselling series from Bill Nye and Gregory Mone Dr. Hank Witherspoon has disappeared. When Jack and his genius siblings, Ava and Matt, find Hank's lab ransacked, they uncover clues pointing them to Brazil--but many questions...