Question: what do you say to the god of death?
Answer: Before Arya runs off to take her place in the Godswood, the Red Woman says some familiar words to spur Arya into action: "What do we say to the God of Death?" The answer, as Arya knows all too well, is, "Not today." But she wouldn't know these words if not for her water dancing instructor, Syrio Forel.