[ Impulse. Ingrained habit. Default mode. She doesn't understand yet, that his propensity for violence is all those things. Because the way he grew up, there was no choice but to dive into the mud. There was never a bridge -- never a safer option. It's true that the child is the father of the man. And it's equally true that the way Hei grew up, he could never afford to be a child. Never afford clemency or honesty. ]

[ He doesn't know how to explain that to her. He can only think, in an abstract way, of men returned from war who have trouble sleeping without their boots on and a rifle close at hand, and how he can understand their difficulty. It's hard for the most primal, powerful regions of the mind to abandon habits that were once crucial to your survival, even when the higher mind recognizes those habits are no longer warranted. What can the habits hurt? the barbed aspects of his nature always argue. ]

[ And, sadly, things like a chance for peace and hope of redemption aren't responses it finds much persuasive. ]

[ Now, he watches Korra's face, wishing he could dispel its shadows. Feeling something in his chest surge, that stupid brim of heartache, reasonless and blinding. ]

[ Quietly, he says, ]

I know you're upset. And angry. And I wish I could say I'll make different choices. But -- [ He pauses, looking past her, at the slow spreading light in the sky. ] Once you've started on a course like mine, there's no right place to stop that means a thing.