When Annatia is unexpectedly transported to the Isle of Marale, a mystical land where centaurs and humans have always lived in harmony, the centaurs there inform her that she is a Traveler. As such, Anna cannot return to her normal life until she resolves the brewing conflict between the centaurs and the neighboring humans - a conflict that is close to erupting into open war. The humans have accused Castaro, a centaur, of setting the fire that killed a man, and they are seeking revenge. Anna knows Castaro is innocent, but if he didn't start the fire, then who did? Soon Anna's dog, Mara, appears on the scene with a surprising ability that deepens their friendship and helps Anna accomplish her mission. As Anna and Mara spy on the humans from their very midst, they discover that there is much more to the dispute than meets the eye.