Cain Morgan is the adopted son of the leader of the Security Force in the kingdom of Heingaria. One day, Cain has a strange dream that brings back memories from his childhood, when his native country Solcia was invaded by the neighboring Aldine. All he remembers is that "everyone went to the island". This mysterious Island of No Return is presently of great interest to the king, who is trying to find why the Elders sent a research team there. The island is rumored to harbor a ring with unseen powers, and the king secretly dispatches Cain to investigate the fate of the people who had ventured there and disappeared without a trace.