A battle fought in the stars...now comes to Earth.

The world of Eternia in the aftermath of Skeletor's war on Castle Grayskull, which he has won after seizing Grayskull and the surrounding city using a cosmic key developed by the locksmith Gwildor. The Sorceress is now Skeletor's prisoner and he begins to drain her life-force as he waits for the moon of Eternia to align with the Great Eye of the Universe that will bestow god-like power upon him.