The Wolf Riders of Keldarra: Book 1: The Stone of Truth by Nathalie M.L. Römer
When the ancient protectors of Keldarra became corrupted, from it came the Wolf Riders. When an ancient discovery was made, from it came the Order of Truth. Wolf riders are savage, knowing only violence and dissention. How or why they started is unknown. Keepers of Truth are only spoken of in whispers behind closed doors. They keep themselves hidden from the world.
Nineteen-year old Marrida is an Acolyte of Truth. Alagur is a Wolf Rider who comes to invade her city. But he is seeking an answer there for dreams.
A well-aimed stone brings their fates together, and sets into motion events that lead to the discovered beginnings of each of their factions, and the discovered truths and lies they uncover, leads them to unconditional love, trust and knowledge that can change the world, and that can set it free from the corruption that exists...