Confrontation at Tu Zin

The Duel at Tu Zin was a small skirmish between Team Avatar, Zuko, Iroh, and Princess Azula of the Fire Nation; the latter attempted to capture or kill Avatar Aang after she and her friends, Mai and Ty Lee, successfully deprived the team of sleep. The duel occurred at the abandoned Earth Kingdom town of Tu Zin. It started off as a three way battle between Aang, Zuko and Azula, but their friends and family soon chipped in. The duel ended in a stalemate with the cornered Azula wounding Iroh with a quick fire blast before escaping without a trace.

Background
Azula was originally tasked by her father, Fire Lord Ozai, to apprehend the exiled nationals Iroh and Prince Zuko after Iroh's treachery and Zuko's failure at the North Pole. Azula found the two and pretended that she was to escort them home under the false pretense that Ozai wanted to be surrounded by family, the only ones he could really trust. However, Iroh suspected the lie and he and Zuko escaped from Azula. Not willing to alert them of her presence and being slowed down by the Royal Procession, Azula recruited Ty Lee and Mai to hunt down Zuko and Iroh. However at the captured city of Omashu where Mai's family had moved to supervise the occupation, Azula's group encountered Team Avatar as they attempted to rescue King Bumi. It was here that Azula learned the identity of the Avatar and although Aang and his friends managed to escape her, she now had an additional target to capture. After their escape, Team Avatar found Toph Bei Fong to teach Aang Earthbending.

Meanwhile, after a quarrel, Zuko and Iroh went their separate ways. Zuko took refuge at a small Earth Kingdom village and befriended a young boy until the villagers discovered his true identity and he was forced to leave again. Iroh decided to covertly track him.

Azula and her group followed Team Avatar in a transport by following the trail of Appa's shedded hair. Team Avatar noticed the transport and attempted to lose them, but Azula's group trailed them into the night, catching up before any real rest could be had, leaving Team Avatar sleep-deprived.

Duel
Team Avatar was grouchy and on edge due to their lack of sleep and constantly having to flee from an unknown enemy. Tensions ran high and, after an argument with Katara and Aang, Toph left the group and bumped into Iroh who was also traveling alone. The two shared a cup of tea and a conversation, neither realizing just with whom they were talking. After washing Appa to rid him of his loose hair, the three remaining members of Team Avatar split up, hoping to divide their pursuers and lead them off course. Katara and Sokka flew on Appa in one direction while Aang used his glider to fly in the other with a bag of Appa's hair, using it to leave a fake trail. While he succeeded in drawing Azula's attention, she realized his plan and sent Mai and Ty Lee to keep an eye out for "the bison".

While Katara and Sokka attempted to find Toph, Mai, and Ty Lee caught up with them. Katara was able to dodge Ty Lee's Chi Blocking attacks but ended up pinned to a tree by Mai's daggers, unable to Waterbend. Ty Lee had better luck with Sokka and he was virtually paralyzed by her. The fight ended when Appa air-slammed Mai and Ty Lee into the river, allowing Katara and Sokka to escape.



Having exhausted the bundle of Appa's hair, Aang decided to wait for his pursuer to catch up in the abandoned village of Tu Zin. As Azula arrived and challenged Aang, Zuko intervened, diverting Azula's attention from the Avatar. The three began a lengthy fight, although most of the time Zuko and Aang were fighting Azula, occasionally sparring with each other when she was momentarily out. Azula managed to knock out Zuko and trap Aang under the debris from a collapsed roof. Just before she could deliver the final blow against a helpless Aang, Katara and Sokka arrived. They succeeded in driving Azula back, but the Fire Nation Princess was completely outnumbered when the reunited Toph also joined the fight. Zuko woke up to see Iroh standing above him. All six then ganged up on Azula and cornered her. She pretended to surrender, but took advantage of Iroh's momentary distraction of finding out that his new-found friend Toph was part of Team Avatar, to wound him with a fire blast to the chest. All four benders struck back at Azula in retaliation, creating a huge explosion. Under cover of the smoke, dust, and steam, Azula mysteriously escaped. A distraught Zuko forced Team Avatar to leave, not allowing them to help the wounded Iroh.

Aftermath
Afterwards, Team Avatar found a location to sleep safely, while Zuko took care of Iroh. Sometime after, Aang prepared to learn Earthbending, while Iroh, partially healed, taught Zuko how to redirect lightning in case Zuko faced Azula again.

Trivia

 * The duel was neither the first nor the last instance in which Zuko and Iroh unofficially teamed up with Team Avatar against a common foe.
 * As stated by the "Avatar Extras" for "The Chase", the beginning of this battle is considered a Mexican Standoff, in which three independent parties all face off against each other. It often takes a while to begin such a battle, because each party fears to make the first move, leaving themselves vulnerable to the third party's attack.
 * This was the first time all four elements were seen being bent at the same time.
 * Coincidentally, the order of the four benders' line-up follows the Avatar Cycle.
 * This was the first time all of the benders of Team Avatar had teamed up together, even though Zuko had not joined the group yet.