Guardians of the Field. Guardians of the Field, #1

A doomsday trigger. A field of magic. A gift that could save the world - or end it. The field of the Esarad is the home of scryers, ageless ones who enter both future and past at will. Karin Anavid must protect her young daughter, born a scryer, from those who would harm her. Maeta, a guardian of the Esarad, guides them both in a desperate race across a land gutted by war. They face a ruler obsessed with finding a hidden route through the ice mountains of Scrinac into the Esarad to annihilate it, and the betrayal of an old friend now consumed by ambition and greed.
And there is Yorajil, a child of light, who escapes with her mother and guardian, yet is led by visions she trusts with a wisdom beyond her years to find her true home. Each one is drawn inexorably toward the ruined city of Alcedama - and the doomsday trigger waiting there.