Avatar, the last airbender Part two Imbalance

Summary: There's something going on in Cranefish Town, and it's up to Aang, katara, Sokka, and Toph to find out what before the conflict between benders and non-benders boils over into violence. But danger lurks when they least expect it and uncovering the truth will reveal a threat unlike any they have ever faced - and a fateful choice for Aang that he can never unmake.