It is a dark time for Eternia. Technology is unheard of. The heroes of Preternia have been forgotten, and the Great Defenders are yet a gleam in the eyes of the world. Bactus, the Devil King, rules over the frightened and cowardly few who can survive in these harsh times. Nobody knows where he came from, only that he has the power to destroy any who oppose him.

In the small village of Teswen, a rebellion has sprouted against Bactus. Its leader, Olius, a strong man with a very regal look about him. Olius is joined by his wife, Jin, and their son, Corr, A bright child with a streak of red through his white-blonde hair. Olius' presence inspires others to stand up to Bactus. Nobody knows why they feel they should follow this man, but they inherently trust him.

During the height of the rebellion, a strange disease starts affecting the citizens of Teswen. Soon, the plague has infected everyone, except, for some reason, Corr. The last thing Olius is able to tell his son before he dies is "Remember Grayskull." After the 8 year old Corr mourns his family, he tries to figure out exactly what his father meant. Grayskull never meant anything to Corr. It was always just "that run-down old fortress." Nobody knows the connection between Grayskull and Corr, or the destiny that awaits him.