Natalia’s smile brings a sense of closure to Kiritsugu’s background story. She could not have known that he would shoot the plane from the situation alone. It would appear that both the mother and son knew the “best” course of action. I’ve always considered apathy a dangerous tool, told others to avoid it and overcome their despair. I’ve fought against the “best” solution in search of a better one, hoped that my own knowledge was inconclusive. But in the end, it is a tool with a role to play. If someone had to, I would gladly be the one to bear that burden. You cannot save everybody, but you can always save others from the cruelty of that fact.