In "Barn Burning," what happens to Sarty which causes him to abandon is father, the rest of his family, and the only life he has ever known?
"Barn Burning" is a story about doing right and wrong. It is also a story about the strength of family bonds and blood relations. This idea of sticking with your family and doing what your family does regardless of whether or not it is the right thing to do is put before readers early on in the story. Sarty was previously in a position where he knew he was going to have to lie to protect his father. Sarty knew it was wrong, but he was prepared to do it.
His father, stiff in his black Sunday coat donned not for the trial but for the moving, did not even look at him. He aims for me to lie, he thought, again with that frantic grief and despair. And I will have to do it.
His father, Abner, is a hate-filled man, but he isn't stupid. Abner realizes that Sarty is beginning to struggle with a moral code, so Abner tries to convince his son that family trumps right and wrong.
You got to learn. You got to learn to stick to your own blood or you ain’t going to have any blood to stick to you.
As the family moves and gets to their new destination, readers see Sarty hoping against all hopes that his father will change.
Maybe he will feel it too. Maybe it will even change him now from what maybe he couldn't help but be.
We see these kinds of thoughts a couple of times; however, Sarty will eventually realize that his father isn't going to change, and Sarty decides he can't continue to be a part of doing wrong anymore. Abner realizes this, and that is why he has Sarty's mother hold him tightly. Sarty breaks free, runs to the house, warns de Spain, and the result is likely the death of Abner. Regardless of whether or not Abner is dead, Sarty has broken his ties with his family by choosing to do what is right rather than sticking to his own blood. Sarty does what he does because his moral code is strong.