A clue on what Bran is going to do in the next episodes of "Game of Thrones" season 7 can be found in the second season 7 official trailer. The hint also confirms that Bran will have a key role to play in the Great War against the Others. Be careful: spoilers on "GOT" season 7 will follow!
The Bran scene in the second season 7 trailer
In the middle of the second "Game of Thrones" season 7 official trailer, we can see a flock of Ravens flying over a northern landscape, then the Night's King noticing something that is flying over his head. Shortly after, we can see Bran exiting one of his trances.
Now, if you look closely at the scene featuring the flock of ravens, you can notice a very important detail: the eyes of one of the ravens suddenly becomes white. That's exactly what happens when Bran controls the mind of another.
You can watch the scene below:
Interesting, isn't it? Since we've yet to see this scene, we can speculate that it will be featured in "GOT" season 7 episode 5 or 6.
What Bran is going to do
Clearly, Bran is going to warg into one of the ravens flying over the White Walkers' army. Apparently, the young Stark is going to use his power to spy on the Night's King, and it's far too easy to predict that he is going to warn Jon, and maybe even Daenerys, about the White Walkers' movements.
The scene also confirms that the Night's King can somehow sense when Bran uses his gift (although whether Bran is forced out of his vision by the Night's King or leaves out of fear is unknown).
In order to understand how important Bran is for the war against the Night's King, we should remember that he's not only able to time travel, he can also take control of animals and people (just like he did with Hodor in the "Hold the door" episode from season 6).
Who is the man near Bran in the Godswood of Winterfell?
It's unclear who the man standing behind Bran in the trailer is. He reminds us of the Three-Eyed Raven, who may still appear to Bran in visions, but he could also be Wolkan, the new Maester of Winterfell. In our opinion, he's probably Wolkan, the man from the Citadel who took Maester Luwin's place after Luwin's death during Ramsay Snow's assault on Winterfell in "Game of Thrones" season 2.
"Game of Thrones" season 7 episode 4, titled "The Spoils of War," airs on August 6 on HBO. Here's the official description recently released by HBO: "Daenerys fights back. Jaime faces an unexpected situation. Arya comes home".