Aang is eager to return to his home, the Southern Air Temple, though Katara worries that evidence of the Fire Nation’s assault on it may upset him. He shows Katara and Sokka around the now-deserted temple, reminiscing about his mentor, Monk Gyatso. While playfully chasing a flying lemur, Aang discovers Gyatso’s skeleton, surrounded by Fire Nation helmets. He enters the Avatar State in his grief. Once Katara and Sokka calm him down, he realizes that he is the last surviving Airbender. As they leave the temple, they adopt the lemur as a pet, naming him Momo. Meanwhile, Zuko stops to make repairs to his ship and is greeted by Zhao, a commander in the Fire Nation navy. Zuko tries to hide that he has seen the Avatar, but Zhao discovers the truth and takes on the task of capturing the Avatar himself, deeming Zuko a failure. Zuko refuses to accept this, as capturing the Avatar is the only way he can return from his banishment from the Fire Nation. Tensions rise between the two, so they challenge each other to a firebending duel (known as an Agni Kai). Zuko wins the duel, but spares Zhao. Zhao then tries to attack Zuko while his back is turned but is stopped by Iroh who intervenes and chastises Zhao for his dishonorable conduct and poor sportsmanship. The Agni Kai sparks a bitter rivalry between Zuko and Zhao.