Enter  Ganon's Dark Tower and Attempt to Seal Him within the Dark World Forever.

An evil sorcerer named Agahnim gains control of Hyrule and uses his power to free Ganon from his prison in the Dark World. After rescuing Princess Zelda from Agahnim's grasp, Link frees the descendents of the Seven Sages and strengthens the magical seals designed to keep Ganon safely locked away.