The Adventures of Alec and Spyro book 4

Alec has been an instructor for the past 3 years, teaching the Dragon Realm about the Human Realm under the identity of instructor Silver. But now, Spyro and Cynder have taken on responsibility of a young troublemaker dragoness named Fog. Fog, in an act of defiance, had run away. Now she is lost in the Human Realm. And for some reason, her body is rejecting it's own existence.