Last year the A Song of Ice and Fire author spoke with Chinese Esquire about his next Game of Thrones book.
He may still be writing The Winds of Winter, but Martin did tease a big role for Lady Stoneheart.
He said: “After Catelyn’s resurrection, it was Lady Stoneheart who became a vengeful and merciless killer.
“In the sixth book, I still continue to write her. She is an important part of the entire book.”
But what exactly will that role be for the undead Catelyn Stark? Fans on the ASOIAF Reddit have some interesting theories.
RoderickRivers says: “I think if she will create a[n] army of Fire Wights (the final war will be Ice Wights, against Fire Wights, with no side being good).
“Or even steal one of Dany’s dragons (Martin said [i]n a[n] interview that the third Head is not necessary a Targaryen), becoming the book version of Night King.
Meanwhile do_not_ask_my_name claimed: “Lady Stoneheart is intrinsically linked with Arya’s story.
“Stoneheart will continue on her revenge rampage, and will host the second Red Wedding.
“But just as Arya ‘created’ her, I think Arya will destroy her. I don’t think it’s a coincidence that Arya is called Mercy, and Lady Stoneheart is Mother Merciless.
“Arya will literally see the ugly face of revenge, and hopefully give her the gift of mercy – symbolically ending her own quest for vengeance.”
Game of Thrones fans will know Lady Stoneheart doesn’t feature in the TV show.
However being “an important part of the entire book” is nonetheless an exciting prospect.
Martin hopes The Winds of Winter will release this year, but fans shouldn’t hold their breath – he has a lot of other projects going on.