From the publishers blurb:
Deep in a hollow hill in the ancient Woldwood lies the Dream Gate: a beachhead for a war against reality that never came to pass. Its custodian, Lord Nuada, has disappeared, and now the oneiric energies have begun to warp the very fabric of the world.
Nuada's subjects - the sapient animals called the Danu - are too distracted to care. Following his disappearance, a civil war ended in a magical catastrophe, and the ascension of cruel predator overlords.
Meanwhile, the 'Goblin King', deposed by Nuada, has returned from Underland. Sending his fungal minions into Nuada's abandoned hill palace, he seeks to retake his throne.
Nearby the dwindling human colonies are still dealing with the aftermath of their war with the giants two decades earlier. Rumors circulate that the leader of the giants may have returned from death, and now treasure hunters arrive to disturb things best left buried.