Game of Thrones Season 7 Alliances: Which Houses Are Working Together?

The Brotherhood Without Banners

The brotherhood is a group of outlaws protecting the commoners from the Lannisters in the name of Eddard Stark, who basically founded the group. So while the brotherhood pledges no official loyalty to anyone, they will most likely fight alongside the Starks, especially against the Night King and his army.

The Hound

The brotherhood recently gained a new member in Sandor Clegane, aka The Hound. He has always been loyal mostly to himself, but you can tell he developed a bit of affection for Arya Stark, which should make it easier for him to fight with the Starks as a member of the brotherhood.