David and Sally are an inseparable pair of kids at Knowre School, solving mysteries left and right. Delve into the book where they solve a mystery about an emerald, and a mysterious group called the Grey Jaguars, as they travel all the way to Peru, ranging from going to cafes with their fend Mark, to getting chased through an underground tiinnel system. Watch as they solve a mystery about the Book of Opara and the emerald, before time can catch up to them.