The Fire Nation army reached the outskirts of Ba Sing Se under a sky streaked with the comet's tail. Sozin's Comet passes once every one hundred years, allowing the firebenders everywhere to experience a rare surge of power.
Tai Lung stood at the forefront of the army with Azula, Ty Lee, and Mai at his side. Azula's eyes shone; she lifted a hand and a great flame erupted in her palm. "The comet has arrived," she said, a satisfied laugh threaded through her words. "My fire has never been stronger." She tried to form a small controlled spark only to watch the flame swell on its own, growing far larger than she'd intended. She let it boil and curl in her hand, amused and pleased by the ease of it. "I wanted to create a small flame, but look at the size."
Tai Lung studied the living blaze for a long moment before answering. "The comet's arrival brought with it a great chi," he observed. "It is filling the world around us. When you ignite fire, that chi is injected into the flame, making it more than ten times more powerful."
Ty Lee asked "Why is that?"
Tai Lung shook his head once. "I don't know." He sounded thoughtful "This is the first time I am seeing this. The chi is selective, it empowers fire only. The comet doesn't feel like a spirit the way the Moon does." He frowned, eyes narrowing as he considered a hypothesis aloud. "Could it be that this is a spirit traveling along the comet, affecting an area much like the fog in the Spirit World?"
Mai cut in "Do you forget where we are? We were about to invade Ba Sing Se, remember?" She exhaled. Tai Lung gave a short chuckle. "No hurry," he said. "We have enough time."
Ty Lee asked again. "Do you think they will surrender?"
Tai Lung's gaze moved to the city walls, to the tiny figures of defenders, the patrols running along the ramparts. "No," he said simply. "They plan to fight."
Azula's eyes glittered with impatience. "If they planned to fight, why wait till the comet arrived? Their odds were already bad enough, is there no one among them who is sane enough to say it is a disaster to battle us during the comet?" She scanned the walls with clear disdain in her eyes. "If I were on their side, I would have harassed the invading army along the way, set traps, anything to delay them and make them miss the comet."
Ty Lee tried to imagine such tactics. "They could dig holes or trenches," she suggested.
Azula nodded. "That would have been better than waiting for the attack to happen," she agreed. Mai snapped them back to the present again. "You are digressing again. Will you start the attack already?"
Tai Lung smiled without humor. He stepped forward and, from his open palm, flung a handful of jade pendants into the air. Then he punched and kicked them with all his might sending them flying into the distance. They spun and flashed; as they reached their apex, many erupted in a sickly green light. Jaded figures burst into being and flew like living projectiles, slicing the air with firebending as they rose over Ba Sing Se's wall. The pendants that continued falling struck the ground detonated in green energy, and from each blast great rocks erupted, charging toward the city like roaring beasts.
Mai said. "Finally. Can we charge now?"
"No hurry," Tai Lung said again. "Let the Jade Warriors fight for a little. I also want to try something Jeong Jeong liked to do."
Azula's brow arched and asked. "What did the old traitor do?"
Tai Lung extended an arm, a great wall of fire erupted in the distance, rising high in the air then moved forward burning everything in its path "He can raise a wall of fire from distance and then drive it forward," Tai Lung said, watching the advancing flame. "That would be an interesting way to attack the wall, no?"
——————
On the wall
The army of the Fire Nation stretched across the horizon like a sea of blood. On top of Ba Sing Se's massive outer wall, the Avatar, Sokka, Iroh, Zuko, and the Earth Kingdom's defenders stood in grim silence, watching. The air was heavy, oppressive, with the glow of Sozin's Comet streaking high above, they knew its fiery presence was going to empower every flame the fire army ignited.
General How raised a spyglass, his voice full of unease. "I don't understand… why are they just standing there like that? Why not charge?"
Sokka replied. "Maybe they're waiting for the comet to grant them power?"
"No," Iroh cut him off immediately, his voice steady but grim. "The comet is already here. Its power has been flowing through us since it crossed the sky. That is not why they wait."
Sokka frowned. "Then… they're strategizing how to attack us."
As if to confirm his words, General How stiffened. His tone rose with urgency. "They're starting. Tai Lung is moving!"
Everyone tensed as Tai Lung stepped forward, he hurled a cluster of green, glowing stones high into the air toward the wall. The defenders watched in dread as the first stone ignited mid-flight with a sickly emerald light. From its eruption, four jade figures emerged, flying straight toward them with a trail of fire behind them.
The lead figure thrust a fist forward, and a massive torrent of fire screamed toward the wall. Aang reacted instantly, sweeping his staff and bending a burst of air that scattered the blaze before it reached the defenders. But before the fire had even dispersed completely, two more pillars of fire roared from the flanks, bearing down on them.
Iroh and Zuko stepped forward in unison, fire meeting fire, their combined bending held the attacks back.
Then the stone beneath their feet exploded. Flames burst upward, forcing them to leap clear.
"Off the wall!" Iroh barked. Aang caught Sokka with a sweep of air and glided them both to safety. Iroh and Zuko used controlled jets of fire to descend, while the Earth Kingdom soldiers scrambled down the stone by bending footholds as they went.
The four jade figures landed hard on the street below, the ground trembling under their impact. Iroh and Zuko froze as they caught sight of them. Three were familiar, Jeong Jeong and two other members of the White Lotus. But the one at their forefront made Zuko's blood run cold.
"Father!!" Zuko's voice cracked with shock.
Iroh's jaw tightened, his fists clenching. "So… you did not survive Tai Lung after all, brother."
The soldiers around them gasped, horrified. Aang's eyes widened in disbelief. "That man… he's Zuko's father? The previous Fire Lord?"
Iroh's tone dropped into gravity. "Yes."
Aang's stomach turned. The enemy he had prepared for all this time, the monster he once thought he would need to face had already been broken, enslaved, turned into a lifeless weapon. His grip on his staff tightened until his knuckles whitened. [I won't let Tai Lung win. I won't let him do this to my friends…]
But before he could even move, the wall behind them shook violently. With a thunderous crack, stone burst outward in an explosion of force. Dust and rubble rained down, and through the breach came another wave of jade light. Figures marched in, leading the charge Bumi and followed by the rest of the White Lotus, their eyes lifeless.
"Spirits…" Sokka whispered.
The defenders pulled together, backs against one another, encircled by jade warriors on both sides. Relief came in a surge of footsteps, Toph, Katara, and more Earth Kingdom reinforcements rushing from the other sections of the wall to join the stand.
Toph's voice was as loud as ever. "You old senile man!" she screamed across the battlefield, locking eyes with Bumi. "Puppet or not, I'm still the greatest earthbender in the world, come face me!!"
"Master Pakku!" Katara's voice cracked with grief as she faced her Jaded mentor. "Please, resist! Don't let Tai Lung control you!"
The street right behind the wall became a battlefield in an instant.
Iroh stepped forward to meet Ozai, fire already curling around his fists.
Zuko squared himself against Jeong Jeong, his eyes blazing with equal parts rage and sorrow.
Katara lifted her arms, water already swirling, as she met Pakku's relentless attacks.
Toph bent her knees, stone trembling under her bare feet, ready to clash with the oldest earth king.
And at the center of it all, Aang, Sokka, and the gathered soldiers braced themselves as the rest of the White Lotus jade warriors pressed in.
The battle to defend Ba Sing Se had begun.