While exploring the caves underneath Hyrule Castle to investigate the origins of the gloom (a dangerous substance which appeared all over the kingdom), Link and Zelda not only find old archeological remains of the Zonai, an ancient race said to have descended from the sky, but also an maleficent mummy held by a bodiless arm, who suddenly reanimates, defeats Link, breaks the Master Sword and rise large structures, once found underground, to the skies above Hyrule, with Zelda vanishing with a spark from a strange amulet found on the site. Some time later, Link awakens in an unknown place on a floating sky island and meets a mysterious spirit called Rauru, which transplanted his arm (the same arm which was holding the mummy) onto Link, since his right arm was beyond saving. Guided by this new ally, Link sets out in an adventure to protect Hyrule, find Princess Zelda and uncover the mysteries of the Zonai.
