The Magic of Prophecy - Book 1 of the Annals of Prophecy

The kingdom of Caldor is at war. As its king tries to bring the light of Toric to the western kingdom of Grelchin, he is beset by problems at home. A plot is stirring against his reign, a killer known only as the Shadow stalks knights in his capital city, and an assassin from Grelchin nearly manages to take his life. Amidst this strife is a shining light, a knight called Tristan who leads his troops. However a strange and portentous moment sets the king against his knight and starts a chain of events that could lead to the downfall of the king, his kingdom and even the peace of the world itself.