After Aang, Katara, and Sokka run out of money, they meet a fisherman who confronts Aang about running away from his destiny as the Avatar. Sokka goes with the fisherman to earn some money and Aang tells Katara about why the fisherman was indeed correct and tells her why he was in the iceberg when they met. Iroh also tells the crew about what happened to Zuko and why he has a scar and the reasons why he is banished. A terrible storm begins to form and Aang must save Sokka and the fisherman, while facing his fears as the Avatar, and Zuko must put aside his selfish reasons for hunting Aang to save his crew. Written by
Did You Know?
Princess Azula makes a "cameo" appearance - she can be seen standing next to Iroh when Ozai punishes Zuko. Technically, this marks Azula's first appearance in the show (outside of the opening credits), but she isn't identified or named this time. The viewers don't even learn of her existence for another eight episodes, and don't hear her speak for another nine. See more
When Katara walks into the cave where Aang is hiding, her shadow overlaps Aang's but we don't see it fall on him. See more
So that's why he's so obsessed. Capturing the Avatar is the only chance he has of things returning to normal.
Things will never return to normal. But the important thing is, the Avatar gives Zuko hope.