The episode five trailer (above), released after last night's "GoT" aired, features the voice of Jon Snow's right-hand man Davos Seaworth delivering the ominous news, probably a reference to the army of White Walkers marching to slaughter every human in Westeros. Their first attack will be the Eastwatch, intel that comes courtesy of the Three-Eyed Raven, a.k.a Bran Stark.
Next week's episode is also titled "Eastwatch," so expect that to be a key plot point, with some major action unfolding at the border, especially since there are only three more episodes left this season.
Meanwhile, Cersei Lannister is surprisingly optimistic about winning the battle for the Iron Throne despite Daenerys Targaryen's dragons. "Whatever stands in our way, we will defeat it," she tells her trusted advisor Qyburn.
And Daenery's authority is starting to worry her closest advisors. "You need to find a way to make her listen," Varys tells Tyrion Lannister.