Desert Song by Angela Dorsey
Series: Horse Guardian, Book 2.
Approx. 35,320 words.
Published on June 2, 2011 by
Enchanted Pony Books.
When Sophie unwittingly puts her foster parents most valuable mare, Aria, in danger, she is afraid she will be sent away. So she keeps her mistake secret, hiding Aria in a remote canyon. But little does Sofie know that a terrible evil is drawing near.