It has been so long now since I read the books that I probably need to reread them. If Jon is the prince that was promised then he has to get Lightbringer some where. Several shows in and no mention of the white walkers. Bran has a vision at some point where the Night's King is there so it is coming. Arya is finally done with training hopefully so maybe we get a clue what the Faceless men want and what their angle is. They have to factor into the endgame somehow.