“It’s tempting to imagine that the Bran vision that immediately follows the episode’s opening credits is a glimpse of either the past or the current march of the undead. But as we learned last season when Bran saw Cersei’s wildfire exploding, this kid can also see the future. If you look closely, it looks to me as though the Night King and his crew (including giants!) are marching on green grass that turns to snow as they cross it.”