Each book in the Mustang Mountain series is a thrilling read filled with stories of friendship, adventure and intrigue.

In the sixth book of the fast-paced series, Becky, Meg and Alisonreturn to the ranch deep in the Rocky Mountains for summer vacation.Becky is thrilled to be home, and even Alison's annoying ways don'tbother her too much. But Alison goes too far when she sends ThomasHorne on a wild goose chase after a phantom horse named Diablo. Atfirst, she had scoffed at the ranch cook's ghost stories of a horsethat haunts nearby Rainbow Valley. But as the days pass and Thomasfails to appear, everyone begins to worry that something terrible musthave happened to him. As the girls set out with a search party, theysoon realize he may not be the only one in danger. Can they avoid thecurse of the ghost horse and make it back to Mustang Mountain Ranchsafely?