We Dine with Cannibals - C. Alexander London

Oliver and Celia Navel have suffered through a whole summer exploring with their father's nemesis Sir Edmund, and are ready to begin a new school year glued to the TV.
But when their mother vanishes (again) in search of the Lost City of Gold: El Dorado, the twins must trek from the ruins of ancient temples through the shadowy forests of the Amazon. This time, they'll need all their reality TV survival skills to brave raging river rapids, furious fire ants, and a most unusual jungle feast. Worst of all, if they can't outsmart the bad guys, they're going to miss all their favorite television shows!