Episode 5 of "Game of Thrones" season 7, titled "Eastwatch," will most likely see more action take place. Also, a reunion with the Stark children may be on the horizon.

The recently released preview trailer for the fifth episode reveals that the Night King (Richard Brake) and his undead White Walker army are heading to Eastwatch, one of the castles at the far end of the Wall.

In the season 7 premiere, "Dragonstone," Jon Snow (Kit Harington) asked Tormund Giantsbane (Kristofer Hivju) and his army of Wildlings to man the Eastwatch castle and keep on the lookout for the Night King and his hordes.

The preview strongly implies that there could be an encounter at Eastwatch between the Wildlings and the undead army. There could be a battle which would see Giantsbane going up against the White Walkers.

Sandor "The Hound" Clegane (Rory McCann) and his group could be at Eastwatch by that time too. In the first episode, he saw a vision in a fire that revealed to him that the undead army was headed to the castle by the sea, which happens to be Eastwatch.

Viewers will have to wait and see in the next episode if the White Walkers will make the first move against the Wall at the Eastwatch castle.

Meanwhile, Jon already knows that Bran Stark (Isaac Hempstead Wright) is alive. In the preview, he mentions that he received a message from him. This could suggest that he knows that his sister Arya Stark (Maisie Williams) is also alive since she returned to their home in Winterfell in the last episode.

If Jon returns to Winterfell, it would see all the remaining Stark children reunite since their last get-together in season 1, which was six years ago.

"Game of Thrones" season 7 episode 5 will air on Sunday, Aug. 13 at 9 p.m. EDT on HBO.