Now, let's go back in time. We need to show just how Shisui and his group managed to overcome the legendary wall that was more famous than the city it protected. Two days prior, the entourage's airship and Appa arrived at the Fire Nation camp, which was located several kilometers away from Ba Sing Se. Many people had gathered there to wait.
The war between the two sides had paused once again. The battlefield was littered with craters, cracks, debris, and burn marks. However, the vegetation was slowly reclaiming the land and erasing the traces of human cruelty.
Perched on the head of his beloved furry friend, Aang looked down at the scene, feeling deep sadness. Although he had come to terms with many things, he was inevitably moved by the thought that if he had acted differently, things might not have come to this.
"Aang, it's not your fault. You know that. I'm not here to tell you that," said Sokka. He approached the young Avatar, patting him on the shoulder as Aang gazed at the former battlefield.
"However, I must tell you something. If you hadn't been frozen and had taken action, the conflict would likely have broken out after your death. Perhaps the Avatar after you would have resolved it, but it would have happened anyway. You know, in that library, I read a lot during the time we were inside," the warrior began, causing Aang to glance at him sideways, eager to hear more.
"Records of wars. For ten thousand years, ever since the first Avatar appeared, there have been wars. Many Avatars lived in peace, like Szeto of the Fire Nation. Others faced conflicts in the spirit world. For example, Kuruk fought an extremely powerful spirit. Shisui told us about Wan Shin Tong's opinion on the matter," Sokka continued. He sat cross-legged and gestured for his friend to do the same since standing while Appa flew made him dizzy.
"I hope for peace. We all do. But that's just the inherent nature of humanity. In 100 years, perhaps it won't be the Fire Nation that starts a conflict. Maybe it'll be someone from the North or South Pole. Perhaps the conflict will come from the Earth Kingdom?" The dark-haired man pointed to Ba Sing Se in the distance, alluding to the impending conflict about to unfold in this city-state.
"Who knows? But we can leave a legacy that makes future generations aware of the consequences of war, so it never escalates to this level again. So I hope you leave a legacy that helps them understand that and more." Sokka looked Aang in the eyes and patted his shoulder again. He had complete faith in him.
"But don't worry! I'll be there to support and help you! Katara won't leave your side either, and neither will Shisui and the rest. We won't let you carry all this weight. You're meant to soar, my friend, not be weighed down by responsibilities." The boy said with a big smile, making the Avatar smile broadly and feel much more at ease.
"Thanks for this, Sokka. Now, how are we going to get into Ba Sing Se? I don't think we can fly over it. They would have tried that already, wouldn't they?" Aang asked curiously. Although Sokka couldn't answer, there was someone on the airship who could.
…
"Flying over, digging through, or breaking straight through the wall is very difficult," Iroh began, recounting his experience with Ba Sing Se from the meeting room of the barracks built in this enclave.
"I tried to bring down those walls with cannons, but they seem to be made of the hardest rock in existence. I even recruited Earthbenders from the colonies to help me dig, but the wall extends very deep, as if roots had grown into it," the old man told the young people gathered around him, including his son, Lu Ten.
"When a barely functional prototype of an aircraft was built, one that was slow and dangerous to fly, I couldn't do it either. I think you two know more about this," Iroh said to his nephew and Shisui, who nodded.
"We tried with the latest model aircraft, even at high altitudes where enemy attacks couldn't reach us. This is where the strangeness of this wall becomes most striking," Zuko began, recalling that moment since he was one of those who participated. Then, Shisui continued the story.
"There's a strange influence emanating from this wall that defends the city, even its airspace. Since it treated us as 'invaders,' no matter how hard we pushed the machinery, we couldn't advance." The Sage shrugged at this point, even chuckling to himself.
"I later confirmed it. That wall is on the verge of becoming a spiritual entity far more advanced than the ice wall at the North Pole. In fact, I have no doubt it has already done so, perhaps even manifesting a physical form that we haven't seen yet," Shisui concluded, filling the room with tension.
"An anima? That's how the Air Nomads know them. Over time, objects gain spirituality and can even become spirits. We call these beings animas. I remember meeting a vase with these characteristics when I was a child. I wonder how it's doing," Aang remarked. Everyone stared at him, even Iroh, who had only met him that day.
"Young Avatar, may I call you Aang?" the old man asked with a kind smile. The Avatar felt at ease in his presence, so he nodded and gestured for the old man to continue.
"Well, such things can indeed happen, although they are extremely rare. If the wall of Ba Sing Se is a spiritual entity, then entering the city by military means would be pointless. Fortunately, my father canceled the project to build a giant drill to tear down the walls," Iroh said, causing the young people to laugh as they imagined a group of Fire Nation soldiers carrying an absurdly large drill and manually turning it against the city wall.
"How do we get into a city like that? It sounds like it's going to be a headache," Suki said, getting to the heart of the matter. Everyone looked at Shisui, who was slowly breaking into a big smile.
"I've been thinking about it. There must be wells in Ba Sing Se, right? A river runs through the city, and there are sewers, too. But we won't enter through those routes. Instead, we'll use a more unique one. Have you heard of underground rivers? Much of the fresh water flows right beneath our feet," the sage said, tapping the floor gently to emphasize his point.
"With Petra and Toph's earthbending, as well as Katara's waterbending for support, I can find a path through all the branches of the underground rivers beneath this ground. I know them because I sensed them once before, and I still remember their layout." Shisui's words shed light on a project that had initially seemed impossible.
"Okay, once we're inside, what will we do?" Katara asked, raising another relevant point that needed to be considered. What would they do once inside Ba Sing Se? Even with the Avatar on their side, they were vastly outnumbered.
"We'll definitely have to set our objectives and assign these tasks to various people," Zuko replied. He knew this matter was just as important as their infiltration of Ba Sing Se because, once inside, they would be in constant danger.
With clear objectives, they could minimize the threat by knowing what steps to take. Lu Ten brought a map of Ba Sing Se, or at least of the city walls, and laid it out on the table.
"Ba Sing Se isn't completely cut off from the world. The wall has gaps and gates through which trade flows. We've launched attacks on those spots from the outside, but we've never been able to take full advantage of them. So, what if we act from the inside? The threat of the supposed spirit is something to consider, but a team could smash through this gate leading to our camp," said Lu Ten, pointing to the gate on the detailed map.
"There needs to be a team to attack that location. It'll be full of enemies, so we'll need heavy firepower. Not to mention, that spirit entity will surely show up." Shisui looked at the group, mentally selecting who would take on the task.
"You'll need an earthbender to handle the gate, right? Leave it to me. I have experience fighting soldiers. Assign Toph to another task." Petra was the first to volunteer, causing the Sage to nod.
"I'll participate too. I think it's a bit lighter. Besides, if that spirit from the wall shows up, I'll teach it a lesson," Azula declared. This caused Shisui to hesitate. Should he let his partner do this? She was pregnant and already showing!
"I can see it on your face. You don't want me to go, but I have to. Pregnancy will never stop me," the princess said arrogantly, lifting her chin even higher. This caused her fiancé to flinch since he hadn't tried to argue and had already lost the argument.
"I'll join them! Come on, Mai. Let's scare the hell out of those guys again," said Ty Lee, narrowing her eyes. Mai nodded, a subtle smile spreading across her face.
"I hope they haven't forgotten my arrows or my daggers sinking into their necks," Mai replied, spinning a knife with considerable dexterity. She barely paid attention to the motion, doing it instinctively.
"I'll join them, or people will think we're just sending girls to fight," said Sokka, raising his hand. Although his comment was a bit rude, they knew it was just a joke, so no one took it to heart.
"I'll join too. They've already had a lot of fun. I'd like to have some, too," Lu Ten said, causing Iroh to frown slightly since he didn't like the idea of his son getting involved in conflicts. However, he knew it was impossible to avoid.
"If I don't go, this fool might do something. Besides, the rest of you are already strong enough for the other task, which I suppose would be attacking the palace, right?" Suki remarked as she playfully slapped her boyfriend on the back of the neck. It was a gentle gesture.
"I'll go with you, too. I think the four of you are enough with the four elements working together. It would be poetic, just like me. I wasted years trying to tear down that wall and infiltrate the city." Guided by his son's suggestion, the old man decided to join the mission, causing Zuko to look at him with concern.
"Uncle, is it okay for you to do this?" the prince asked, causing his uncle to chuckle softly. He nodded slightly as he settled into his seat, eager for a cup of tea.
"Of course! As your elder, how could I not join in? If it weren't just a symbolic gesture, it might be seen as a more serious declaration. Ozai would surely join in as well." Iroh replied, looking at the four who would be working together by association.
"A waterbender who looks like he's on drugs, a firebender with flames like the sun, a rare but brutal airbender, and me, the best earthbender of them all!" Toph exclaimed, pointing at Shishui, Zuko, the Avatar, and then herself.
"We really are the four elements. And yes, we'll attack the palace, as well as anything else of importance we see along the way. I promised that guy I'd destroy those things," said Shisui, narrowing his golden eyes and holding back his rage and murderous intent.
"We'll be facing enemies who could be troublesome, so the army will need to storm the city once the gate falls. However, they must be ordered not to attack the civilians. We just want to clear the way. That way, your side can support us," Zuko said, looking at his younger sister. She nodded in agreement.
"All right. I'd like to deal with the leader of the Dai Li or that strange group I won't even bother to remember," Azula replied, creating a small blue flame in her right fist and holding it up to emphasize her words.
"Now, let's plan exactly how we'll infiltrate through the underground rivers..."