Hex Witch of Seldom — Nancy Springer

This contemporary fantasy by award-winning author Nancy Springer sweeps readers along on a girl's journey of enlightenment and transformation

Raised in the Allegheny Mountains of Pennsylvania by her grandpap, Bobbi Lee Yandro has been seeing things that aren't there for years. Afraid she's going “all the way crazy” like her institutionalized mother, she receives an unexpected gift for her almost-sixteenth birthday: a box of her dead father's journals. Wright Yandro was killed in Vietnam when Bobbi was a baby, but the poems he left behind stir something inside her, awakening visions of wild horses. When her grandfather buys her a black mustang with eyes of blue fire, she instinctively knows its name is Shane.
 
On the day the vet arrives to castrate Shane, Bobbi helps the horse escape. Soon she and Shane are fugitives on a journey that takes Bobbi far from Canadawa County to a village deep in the mountains. Here she meets Hazel Fenstermacher, also known as the Hex Witch of Seldom. Hazel introduces Bobbi to the Twelve of the Hidden Circle, who include a king, a sorceress, a poet, a trickster, and a dark hero. But one of them is out to steal Shane's soul, for he is no ordinary horse. As Bobbi uncovers the secrets of the Circle, she must employ her special gifts to save Shane and shape her own future.