Mandate of Heaven (фемслэш)

The night Ozai tries to take the throne goes much differently. With Ozai and Ursa dead, and Azulon mortally wounded, Iroh is forced to take the throne- and to adopt his orphaned niece and nephew. Years later, Zuko is the heir to the throne, and Azula is not happy about it. Short of outright assassination (which she hasn't entirely ruled out), there's only one way to take the throne from Zuko- find and capture the Avatar, to show that she is the worthier heir. Of course, things are never that simple.