In this second KC Flanagan Girl Detective™ adventure, KC accompanies her brother, Dad and Dad's new significant other to the lush Island of Isla Mujeres, just off Cancún in the Mexican Yucatan peninsula. Only looking forward to a relaxed vacation in the tropics, KC nevertheless stumbles on a plot to steal sunken treasure and eventually helps corral the criminals. Along the way she learns a lot about the magnificence of ancient Mayan culture, adopts a Kinkajou and gets in and out of danger.