Prince of the North — Harry Turtledove

A great leader rises when forced to defend his troubled lands against an onslaught of monsters in the second book of this remarkable fantasy series featuring Gerin the Fox

Peace in the North has been fragile and tentative in the five years since the terrible Werenight, when the light of four full moons transformed men into beasts. Now cut off completely from the Elabon Empire, the land is in violent dispute, squabbled over by minor barons hungry for greater power. Gerin the Fox is one of the few who stand firm against the encroaching chaos, but his own life has been violently shaken, first by a heartless betrayal and then by the kidnapping of his young son. Having angered a vengeful deity, he cannot look to the gods for support. Yet it is Gerin to whom the people must turn when an earthquake tears their land open, undoing an ancient warding spell and releasing a host of ravaging beasts from the dark underground.
 
The stunning sequel to Werenight, Hugo Awardâ€"winning author Harry Turtledove's Prince of the North is a magnificent work of fantasy fiction. The master builder of wondrous worlds and alternate histories works his literary sorcery once again in this richly imagined tale of war, magic, gods, and monsters.