Dragons in Areth each have a single predestined rider and life mission, given to them by the Oracle. Kira and her dusk dragon, Longfang, must find the third orb to save the Oracle, leader of all dragonkind. Following a path beset with dangers and traps, the four dragonriders must reach the twilight world of the Castle of Shadows. Kira knows enough to be anxious. What twisted sacrifice will this orb demand?