There was no helping her tears. For they would leave Po behind… She cried into his shoulder like a child. Ashamed of herself, for it was only a parting, and Bitterblue had not wept like this even over a death. ‘Don’t be ashamed,' Po whispered. ‘Your sadness is dear to me. Don’t be frightened. I won’t die, Katsa. I won’t die, and we’ll meet again.
Your sadness is one of the things that makes you beautiful to me. Don't you see that? I understand it. It makes my own sadness less frightening." (Brigan)
And of course she understood now why her body wanted to run whenever he appeared. It was a correct instinct, for there was nothing to be got from this but sadness.