Scotty is a lonely, scared Earth boy who goes to the faraway planet of Kestrellia for the summer to live with his dad. He meets an alien boy named Aldy, and the two become fast friends. Aldy has a secret. As the son of the king, when he turns ten, he has to go on a quest for a beautiful blue jewel, the Blue Kyrolite, high up in the cold mountains of Kestrellia to prove he is worthy to become the next king. Aldy asks Scotty to go with him on his quest for the jewel, which they soon find out is more difficult than expected. Along the way, Scotty learns how to deal with his fears while the boys realize that they are not really supposed to be looking for a beautiful jewel after all...but what is it they are supposed to find?
