With only Gibson and a half damaged Super Robot, Chiro must mount a rescue against the Citadel of Bone to save the Hyperforce from tortuous brainwashing by Mandarin and Sakko. As Chiro and Gibson explore the citadel's nightmarish interior they discover secrets of Chiro's past as well as a secret of Skeleton King himself. Can Chiro harness the Power Primate, free his friends, and defeat Skeleton King before he unleashes a wave of evil on Shuggazoom?