When the show announced the news, they did so with a new trailer... and boy has it sparked a new theory. That theory is that Bran Stark is the Night King.
Wot?
The theory suggests that Bran Stark is the Three Eyed Raven - which is an ancient being that can see both the future and the past.
He has seen the time when the White Walkers were created by the Children of the Forest.
When he saw this, he asked one of the Children - Leaf - why they made them and caused this HUGE mess.
She replied: "We were at war. We were being slaughtered. Our sacred trees cut down. We needed to defend ourselves."
Bran replied: "From who?"
Leaf simply said: "From you".
Those are the words that kicked off the theory.
In the latest trailer, fans spotted that all the remaining Stark children were features, aside from Bran.
Or, maybe he appears in a more cryptic way? At the end of the clip, there is a cold mist that signifies the Night King and his army, are coming. Is Bran the Night King leading the army?
We guess we'll just have to wait and see.