It was on the long voyage south that Aang dreamt of Roku.
After his friends had successfully hijacked the Fire Nation warship, and Katara had shoved the crew over the side, she had come back to fetch him on Appa. Then, after swearing the tribespeople on board to secrecy, she had told them how reports of the Avatar's death had been greatly exaggerated and allowed them to meet him. The children, especially, had enjoyed it, crowding around and asking him a million questions about his Sky bison and his glider and his adventures.
The voyage itself was going well enough. A combination of Toph's metal bending, Katara's waterbending, and Aang's Firebending (he didn't know much, but his time with Jeong Jeong had taught him how to generate a flame at least- but he still made sure that nobody else was in the room when he did it, having learnt a painful lesson) were enough to move the ship, the Zoryu, south at a good enough pace.
It was on the second day of the voyage that the Fire Nation avatar before him manifested to him in a dream, his red robes and long flowing white beard managing to wave in the wind despite there not being a wind.
"There is something you need to know," Roku had told him. "If this war is to end, you need to understand how it began. Tomorrow, I will help you understand."
"Why not now?" Aang had asked.
"Because it's going to take a while, and I'm giving you a chance to tell your friends first."
So he did.
"I'm going away for the next couple of days," he announced.
"What? Where?" Katara asked.
"Into the Spirit world to talk to Roku."
"Why didn't you lead with that?" Sokka demanded. "You made us think you were going on some secret mission."
"He has important information about how the war started, and he wants me to know so I can do better at ending it apparently."
"Any information that gets us a better chance at defeating the Fire Nation is good information," Toph said, and the others were inclined to agree.
"Good luck, Aang".
Aang smiled at them, went into his cabin, and shut the door. He arranged his mattress on the floor to give him a comfortable seat, and sat down on it cross-legged.
He closed his eyes, and took a deep breath.
He didn't know how long he was there, concentrating, before the darkness was replaced by the brightness of the spirit world. He was on a clifftop, overlooking a vast forest that stretched into the distance. Standing beside him was Roku.
"Avatar Aang," he said.
"So what is it you want to tell me? Must be a long story?"
"I don't want to tell you anything. I want to show you. I can show you my memories, memories of my childhood best friend long ago."
"What does that have to do with anything?"
"Because that boy's name was Sozin."
As Aang took in the revelation that Roku's best friend had been the Firelord who had started the war and wiped out the Air Nomads, the scene changed. Now, they were in the physical world again, but the physical world of about 180 years previous. They stood in a large room flanked by pillars, adorned with rich red tapestries. At the front of the room, flames danced along a raised platform, behind which a man sat. It was not a man Aang recognised, but he was wearing a familiar headpiece so he could guess.
"The Fire Palace?"
"Yes, this is the throne room, and that is the Fire Lord before Sozin. Firelord Zuiho was his name. A wise and fair ruler, by all accounts. They called him Zuiho the Just. There were even rumours that he would disguise himself to walk in the city and arbitrate disputes between citizens there."
Zuiho was talking to a man and a woman, nobles by the look of them. The woman had a child hiding behind her knee.
"...my son, Sozin, is in need of companions, as is tradition," the Firelord said. "He is five, and is about to start his royal tutelage. It can get lonely by yourself."
He addressed the boy directly. "What's your name, young man?" The child only shrank away.
The mother laughed, and answered for him. "His name is Roku, and he's shy."
Aang looked at Roku.
"Yes, that is indeed me."
Zuiho clapped his hands together. "Well, Roku, you'll do nicely. Welcome to your new life!"
"Did they know you were the Avatar at this point?"
"I did ask Zuiho after I found out who I was, and he said that he didn't, no."
The scene changed again. Now, they were outdoors, watching two teenagers sparring in the yard. By now, one of them was recognisable; he was much, much younger and his hair was brown, but it was undoubtedly Roku. His sparring partner was shorter, and wore the headpiece of the Crown Prince of the Fire Nation.
This must be Sozin, Aang thought. They watched as young Roku and Sozin traded blasts of fire, with Sozing gaining the upper hand until he backed Roku up against a tree. Roku tripped over one of the roots, but was caught by Sozin- who promptly dropped him.
"And that's how you do it," Sozin crowed with mock smugness.
"One win, and you immediately become insufferable."
"Is it really only the one? I counted at least four, or five."
"Over the course of our tutelage together, Sozin and I grew to become fast friends, although we often found life in court boring," old Roku said.
A group of women walked past, causing Roku's head to turn- which did not go unnoticed by his friend.
"Go on, then, talk to them."
Roku came within a second of shouting and running after them, but nerves overcame him and he collapsed to the ground.
"What can I say? Young love is hard even if you are the Avatar. Don't worry though, it gets better."
Aang wondered whether it was possible to blush in the spirit world.
The scene changed again. Now, Roku and Sozin were descending a flight of stairs in front of a group of people, with a visibly older Firelord at the front of the crowd.
"Ah, this is our sixteenth birthday,"
"Our?"
"Yes, our. Me and Sozin had the same birthday."
A commotion came from the back of the room. Three men pushed through the crowd, until they stood next to Zuiho and addressed the two. "We bring urgent news!"
"What is it?" Sozin asked with worry, looking at his father.
"Our news concerns your friend, Roku. Or should that be, Avatar Roku."
"Avatar?" Sozin whispered, looking at his friend. "Oh, this is great."
And he turned and kneeled towards him, followed by the rest of the crowd.
"Unfortunately, with the revelation that I was the avatar came the obligation to take up the avatar's duties- including, to begin with, training. I was forced to leave my comfortable life and all my possessions behind. Well, nearly all my possessions..."
And the scene changed to Roku's bedroom, where he sat glumly on the bed. There was a movement at the door, and Sozin entered. "So when are you leaving? Are you packed?"
"No need for that. I can't take any possessions with me. I'm leaving tomorrow."
"That soon?"
Roku only nodded.
Sozin suddenly had an idea. "Hey, take this when you go." He took the headpiece of the crown Prince off and pressed it into Roku's hand.
"But this belongs to the crown Prince. I can't take this."
"The Crown Prince bequeaths it to you".
Roku put the headpiece on, and the scene changed again.
"As a Fire Avatar, my order of learning the elements went Air, Water, Earth. So first, I went to an Air Temple to begin my training. And there I met someone who is of interest to you."
Young Roku was dressed in air nomad clothing, and surrounded by young nomads. One of them seemed familiar. "Is that Gyatso?" Aang wondered.
"The very same."
Young Gyatso was just as mischievous as old Gyatso; he was constantly demonstrating new glider tricks he had learned or invented, and blasting unsuspecting passers by with air. It also turned out that he had begun his habit of throwing fruit pies at people early; Roku was his willing accomplice in much of it.
"It's cool that you were friends with Gyatso too!" Aang stated enthusiastically.
"Some friendships are so strong they can even transcend lifetimes," Roku replied.
The next few scenes were a training montage of Roku learning waterbending and earthbending.
"I struggled with waterbending the most, similar to how you struggle with earth. It's the opposite element to our natural one, which Avatars always have trouble with. It will come. It did for me."
Finally, they watched as Roku entered the avatar state for the first time and proceeded to bend all four elements at once, making him a fully realized avatar.
"With my training over, I returned home. In the intervening time, Firelord Zuiho had sadly died, making Sozin the new Firelord."
Roku, now with a flowing beard, stepped into the hall that the first memory had taken place in.
"Firelord Sozin, it's good to see you."
A cold voice answered from behind the flames.
"It is customary for Fire Nation citizens to address their Firelord as "your majesty" and bow, even if they are the Avatar."
A look of confusion crossed Roku's face for a second, before the flames suddenly vanished and Sozin smiled at him. "But you're the exception."
The Avatar and the Firelord hugged.
"It had been several years, but nothing had changed at all. And there was another happy reunion in store."
The hall changed, suddenly bedecked in flowers and filled with seats. Roku sat at one end of it, with one of the women he hadn't been able to talk to earlier."
"I told you it gets better," Roku said, his eyes sparkling. Her name was Ta Min, and we loved each other a lot. This was our wedding day."
Aang watched the celebrations.
"Sadly, the happiness was not to last."
Aang saw Sozin approach Roku and ask him for a private word, heading out on to the balcony.
"I've been thinking."
"What, again?" Roku asked jokingly, but Sozin was being serious.
"For the last hundred years, our nation has been on the up and up. The Air Nomads are disparate, the Water Tribes are primitive, and the Earth Kingdom is divided. We, on the other hand, are united and prosperous. I was thinking we could share that with the rest of the world."
Sozin", Roku said slowly, "you'd better be talking about trade agreements and aid programmes."
"There's no guarantee they would accept those. I want us to spread our ways through force of arms if necessary."
Roku was horrified. "Sozin, no! That's quite possibly the worst idea I've ever heard! I'm the Avatar. My duty is to all four nations. I cannot allow you to plunge them into war like that. Do not speak of this again."
And Roku walked off, leaving Sozin fuming on the balcony.
"Sozin did not speak of it again, not to my face anyway. But that doesn't mean he didn't do it.
It was the throne room again, and the doors opened with a crash as an irate Roku came bursting through the doors.
"What in Agni's name are you playing at Sozin? Taking territories in Earth Kingdom territory? We discussed this, and I'm sure I expressly forbade this."
"Who are you to order the Firelord about like this? You are my subject, and you will do as I say."
"No. You are the one who is subject to my authority, and I'm putting my foot down. This ends now."
Roku turned to walk away.
Sozin's face twitched, his anger building quickly until he could no longer hold it in. He jumped down and unleashed a blast and of fire that did absolutely nothing. When it dissipated, he saw Roku, still with his back turned, but with one hand outstretched.
When the Avatar turned around, his eyes were glowing.
"You shouldn't have done that, my friend."
Thirty seconds of extreme violence later, the throne room had been all but levelled and Sozin hung helplessly from a pillar of rock. Roku flew up to him.
"Several of my past lives have counselled me to kill you. Fortunately for you, I have chosen to follow the action suggested by my most recent past life and give you one more chance. Pull out of the earth kingdom and demilitarise and I shall let you live. Fail to do so, and I'll make sure to bring about an early succession."
Sozin could only hang his head in shame at being defeated so quickly. Roku left him to it.
"I didn't see the Firelord again for 25 years. I spent that time in the other nations, all the time keeping an eye out for Fire Nation military presence."
They watched Roku fighting pirates alongside women Aang recognised as Kyoshi warriors, negotiating with a man who wore the regalia of an Earth King, and riding a Sky- bison with Monk Gyatso, who now had his tattoos. Then they watched Roku and Gyatso riding Fang, Roku's dragon.
"Remember, there was more to my life than Sozin."
Eventually, the scene changed to a volcanic island in the middle of the night. Suddenly, the ground shook. Roku and Ta Min fell out of bed, and saw what was happening; the Volcano was erupting. "Get everyone to safety! Evacuate the island!" Roku shouted. He took the time to kiss Ta Min goodbye one last time, and then he was gone.
"Avatars get old too. I was an old man fighting the volcano, while dealing with the poisonous gases. It was hard work, even with the use of the Avatar State and all four elements at my disposal."
Roku began directing the pyroclastic flow of the volcano away from the village, trying to buy time for the evacuation. However, he was an old man and so he was beginning to ail and flag until-
"Hello old friend. Need a hand?"
"Sozin?"
"I had not seen the Firelord for a very long time and we had not parted on the best of terms, so him actually coming to help me was very unexpected."
"Get the other volcano. Try to stop it erupting!"
Sozin took up position on the edge of the volcano, and began directing its heat through himself. As it streamed through his body, the rocks cooled and began to harden. Eventually, they decided that there was nothing more that could be done, and Sozin led Roku down the mountainside towards their two dragons.
Just as they were approaching them, Roku got a faceful of poisonous gas from a hidden vent. He collapsed to the ground, unable to move any more.
"Sozin, help me." He cried.
Sozin turned around and began to move back towards him, but stopped. Indecision played across his face. Aang could see him wrestling over whether to choose friendship or the world. Roku could see it too.
"Please!"
Sozin turned away.
"I want you to know that this is nothing personal. I'm truly grateful for all your years of friendship and if it were up to me I would save you. Sadly, you stand in the way of my plans, and this is bigger than us. Your death is the gateway to great things."
And with that, Sozin walked away. Roku could only watch in disbelief, that turned to resignation.
He heard a rumble above him, and turned to see an enormous explosion at the top of the mountain. As the pyroclastic flow surged towards the Avatar, he closed his eyes and thought of his wife.
"After my death, he began planning in earnest for the war and on the day of Sozin's Comet 12 years later he came for you."
"What's the point of all this?"
"This war began with a falling out between the Avatar and the Firelord, and the Avatar failing to go far enough to stop it. To truly end the war, maybe that has to be reversed."
"Are you suggesting I make friends with the Firelord? I don't know if you've noticed, but Ozai is not a nice man."
"Where did I say anything about Ozai?" Roku asked. "Do what you must, even if it conflicts with your moral codes, but reconcile afterwards."
With that, Aang woke up. It was noticeably colder in the cabin.
They must be approaching the pole.
Author's note; I am aware that this is very similar to the episode "the Avatar and the Firelord", but I felt that like the episode "the Earth King" this episode was too important to be left out. Don't worry, though, all chapters after this should be sufficiently different.I at least changed the dialogue and added extra bits.