When unnatural wildfires ravage the prairies, many of the horse herds and human clans are burnt. Precious warmblood mares disappear and mysterious stealthcats are killing foals, forcing a dying stallion to seek help from the guardian unicorns.Following a confusing prophecy that threatens the whole world, Mystery, the youngest unicorn, is sent to solve the problem. But being of horse parents, Mystery is filled with doubt and scared he has no power. Nevertheless, accompanied by Laila, a young woman, and Meda, her healer dragon, he determines to confront whatever evil is behind the devastation.