Helm of Shadows - The Grey Riders, #3

Now that they have cleared Buck Bydecy's name and brought justice to the man who made Andyn Eleandir a widow, the Grey Riders fly their pegasi to the eastern wilderness, seeking clues to the prophecy that seems to direct their path and predicts a climactic battle between Light and Dark. Yet the specter of the Dark Rider, Zhinia Margoth, haunts their steps - they know Margoth gathers her forces to conquer the Northlands, regain her ancient kingdom and begin a new reign of terror. With the beloved Alenar sisters on a secret mission to the evil-dominated lands to the south, Dar Cabot and his friends race to find the mythical Helm of Shadows before Margoth does, knowing it is a key to her plans for conquest. Great peril awaits as they travel through trackless forests and crumbling ruins, battling Margoth's troops, undead horrors and dark dragons alike, seeking the clues they need. But time is running out. If they do not find a way to defeat Margoth, all the lands and their people could fall to her hateful wrath.