Emma and Martín swap the cool Chicago fall for the hot jungles of the Puuc Hills when they dive into the myth of the Child King of Uxmal. There, they meet Nicte the healer.

Nicte is determined to save her village from constant droughts and the burden of their ruthless king. She's following rumors of a prophecy, which leads her to three strange items: a giant egg and a drum and rattle that will only play for the rightful king of Uxmal.

Emma and Martín are eager to help Nicte follow the prophecy when they are yanked out of the jungle--and discover that there's a page missing from their book! Can the twins find a way back into the legend to save Nicte's village, or is this the end of the story?