Authors Note: In this AU, Zuko joined the Gaang some time before they met Hama (Episode 3.8 The Puppetmaster)
Aang stands with a blade against Zuko's neck. Katara's world stops. Hama starts to laugh.
Later, the scene will continue in Katara's nightmares.
She will hear herself scream and beg. She will plead not him, please, please, not him but nothing will stop the blade from cutting deeper. She will watch powerlessly as Zuko falls to the ground, blood pooling around him. She will see his golden eyes, once so full of fire and life, become dull. Her knees will give out and she will kneel in the grass, helpless. She will reach for him, desperate to heal, desperate to hold. But she will be unable to move forward, just as Aang is unable to drop the sword, paralyzed. Hama will laugh and proclaim justice while Katara's world falls apart and her screams fill the air.
In her nightmares, Katara will not be able to save Zuko.
But in reality, Katara becomes a blood bender. Hama stops laughing.