'GOT' Season 7, Episode 6 Synopsis: What Happens In 'Beyond The Wall?'

Perhaps the biggest battle yet is set to happen now on "Game of Thrones," but it will have nothing to do with the Iron Throne.

After Bran's (Isaac Hampstead-Wright) vision of The Night King and his Army of the Dead marching on the wall at Eastwatch-By-The-Sea, Jon Snow (Kit Harington) realized he needed to find a way to convince the Southern armies to commit to the fight before it was too late. The only way it will be possible is if he brings a Wight to King's Landing to show Cersei Lannister (Lena Headey). Along with Jorah (Iain Glen), Gendry (Joe Dempsie), Tormund (Kristofer Hivju), Thoros (Paul Kaye), Beric Dondarrion (Richard Dormer), and The Hound (Rory McCann), he set off beyond The Wall to capture one.

Now, in episode 6, the men will encounter a much bigger threat than they realized, as the Army of the Dead and the Night King begin to close in on them.

"Death is the enemy. The first enemy, and the last. And the enemy always wins," a voice warns in a promo clip for the episode.

It appears the men, who can also be seen in the clip crouching together in a circle as the dead approach, will realize quickly that their enemy is more powerful than any of them, including Jon and Tormund, who saw the army at work at Hardhome before this, realized. They are also seen in the clip running and fleeing back towards the Wall—apparently trying to save themselves.

Meanwhile, back in Westeros, Daenerys (Emilia Clarke) and Tyrion (Peter Dinklage) seem contemplative at Dragonstone. Not only did they disagree about how Dany handled things after the loot train battle with the Lannister forces, but they could now both be at a loss following Jon and Davos (Liam Cunningham) departing from their base. Though Dany didn't believe Jon at first about the White Walkers, and refused to give him help until he bent the knee to her, she now sees him as an ally, and believes the threat may be real.

Also in Westeros, back in Winterfell, it also seems as if the plan Littlefinger (Aidan Gillen) has put into effect, in the hopes of driving a wedge between the recently reunited Sansa (Sophie Turner) and Arya (Maisie Williams), is working. Following Arya breaking into his chamber and finding the scroll Sansa wrote to Robb (Richard Madden), telling him to bend the knee to Joffrey (Jack Gleeson), it appears she will confront her sister about where her loyalties lied after Joffrey imprisoned Ned (Sean Bean) and later had him beheaded. Knowing Arya is now a trained assassin, Sansa, who was forced by Cersei and Joffrey to write the scroll for her own safety, could express fear as a result, and Arya may ask her sibling why she seems to be so worried about her.

"You're scared, aren't you? What are you scared of?" Arya asks in the clip.

"Game of Thrones" airs Sundays at 9 p.m. EDT on HBO.