What Did I Do?

I thought that the ending was remarkable, especially more Johnson's performance in that moment where he is, makes a split second decision to kill his son. That also, the, what did I do had that he sort of repeats over and over again, had so much resonance because he obviously made this instinctual decision to protect Ellie. And it just immediately ties into Kathleen's being, you know, her statement about you can't escape fate.