Prince Zuko: [to Iroh] You sent this, didn't you? I found the secret history, which, by the way, should be renamed the history most people already know. The note said that I needed to know about my Great-Grandfather's death! But he was still alive in the end.
Uncle Iroh: No. He wasn't.
Prince Zuko: What are you talking about?
Uncle Iroh: You have more than one Great-Grandfather, Prince Zuko. Sozin was your Father's Grandfather. Your mother's Grandfather was Avatar Roku.
Prince Zuko: [Zuko looks shocked] Why are you telling me this?
Uncle Iroh: Because understanding the struggle between your two Great-Grandfathers can help you better understand the battle within yourself. Evil and Good are always at war inside you, Zuko. It is your nature. Your legacy. But, there is a bright side. What happened generations ago can be resolved now, by *you*. Because of your legacy, you alone can cleanse the sins of our family, and the Fire Nation. Born in you along with all the strife is the power to restore balance to the world.
[Iroh opens a secret compartment, revealing Roku's crown, and offers it to Zuko]
Uncle Iroh: This is a royal artifact. It's supposed to be worn by the Crown Prince.
Aang: Roku was just as much Fire Nation as Sozin was, right? If anything, their story proves anyone's capable of great good and great evil. Everyone, even the Fire Lord and the Fire Nation, have to be treated like they're worth giving a chance. And I also think it's about friendships.
Toph: Do you really think friendships can last more than one lifetime?
[Aang takes hold of one of Toph's hands]
Sokka: I don't see why not.
[Katara takes hold of Toph's other hand]
Sokka: Well, scientifically speaking, there's no way to prove that.
Katara: Oh Sokka, just hold hands.
[Sokka takes hold of Katara's free hand]
Avatar Roku: I'm sparing you, Sozin. I'm letting you go in the name of our past friendship. But I warn you, even a single step out of line will result in your *permanent*... end.
Fire Lord Sozin: [to Avatar Roku] Without you, all my plans are suddenly possible. I have a vision for the future, Roku.
[Sozin leaves Roku to die]
Avatar Roku: When love is real, it finds a way... And being the Avatar doesn't hurt your chances with the ladies either.
Young Sozin: Right from the start, I was destined to be Fire Lord. And although we didn't always know it, you were destined to be the Avatar. It's an amazing stroke of fate we know each other so well, isn't it? Together, we could do... anything.
Young Roku: [Cautious] Yeah, we could.
Young Sozin: Our nation is enjoying an unprecedented time of peace and wealth. Our people are happy. And we're so fortunate in so many ways.
Young Roku: [Growing more concerned] Where are you going with this?
Young Sozin: I've been thinking. We should share this prosperity with the rest of the world. In our hands is the most successful empire in history. It's time we expanded it.
Young Roku: [Firmly] No! The four nations are meant to be just that, four.
Young Sozin: [Emphatically] Roku, you haven't even stopped to consider the possibilities.
Young Roku: [Angry] There are no possibilities. This is the last I want to hear about this.
Avatar Roku: [Narrating, to Aang] That was my first real test as the Avatar. Unfortunately, it was many years before I learned that Sozin had gone ahead with his plan desite my warning.
Young Sozin: With Roku gone and the great comet returning, the timing was perfect to change the world. I knew the next Avatar would be born an Air Nomad, so I wiped out the Air Temples. But somehow, the new Avatar eluded me. I wasted the remainder of my life searching in vain. I know he's hiding out there somewhere, the Fire Nation's greatest threat... the last Airbender.
Prince Zuko: Wait. I need to ask you something. What do you remember about our Great-Grandfather's history?
Azula: Oh, Zuko, it's so strange how your mind works. Fire Lord Sozin began the war, of course. He spent his early years secretly preparing for it, but he was as patient as he was clever. He famously waited for the comet, later renamed Sozin's comet, and used its power to launch his full-scale invasion of the world. In the end, he died a very old and successful man.
Prince Zuko: But, how did you die?
Azula: Didn't you pay *any* attention in school, Zuko? He died peacefully, in his sleep. He was ancient.
Azula: It's never too early for a sitting with the court painters, Zuko. Make sure he gets your good side.