The weeks and months crawl past as Zuko awaits his destruction.
Of course it can come from within as easily as from without.
Lady Kaiza smiles politely. She is pleasant, and she is patient.
Lady Kaiza doesn't complain about the fact that the Fire Lord has housed her in the most distant and neglected wing of his palace or that he routinely ignores her requests for an audience. Let his ministers handle it.
Katara is traveling. His spies track her movements from city to city, nation to nation, port to port. Her path crosses that of Avatar Aang. They see each other in private (his spies report) and then... they each move on.
Katara is circling around the world, and eventually her path turns back toward the Fire Nation.
Among other things, his spies have discovered her favorite tea, or what passes for tea. On an impulse, Zuko begins ordering it in bulk from the northern water tribe. The first sip tastes like fermented sea water. The second tastes like the juice from a half-picked sea prune. It only gets more and more putrid from there. Remembering his uncle's advice, Zuko has begun serving it at state occasions. He enjoys watching his ministers blink tears from their eyes and purse their lips, sip by sip by sip.