" I have never liked you, Cersei, but you were my own sister, so I never did you harm. You’ve ended that. I will hurt you for this. I don’t know how yet, but give me time. A day will come when you think you are safe and happy, and suddenly your joy will turn to ashes in your mouth, and you’ll know the debt is paid.—A Clash of Kings "

― George R.R. Martin , The Wit & Wisdom of Tyrion Lannister