HBO has released new stills for the "Game of Thrones" season four finale, but an Emmy nomination submission may have given away a key part to the ending.

[Warning: article contains spoilers]

Vanity Fair reports show runners Dan Weiss and David Beinoff have submitted Sunday's finale titled "The Children" for Outstanding Prosthetic Make-up Emmy award.

If you've read the books, your mind will probably flash to the appearance of zombie Catelyn Stark, better known as Lady Stoneheart. In the novels, Stark is overcome with grief over the death of her son Robb Stark and she scratches her face until she bleeds. After the great display of emotions during the Red Wedding massacre, Catelyn's neck is sliced open and she dies.

However, the "Game of Thrones" Red Wedding episode skips over Catelyn scratching at her face and the last time fans see her is in the dinning hall in season three.

HBO show runners could easily leave out the appearance of Lady Stoneheart, but the Emmy nomination fuels rumors of Catelyn Stark's return. Actress Lena Headey, who plays Cersei Lannister, started the conversation when she posted an Instagram photo of rocks laid out in the shape of a heart. Heady captioned the photo: "my stone heart."

Headey is known to give nods to show fans on her Instagram account. She posted a photo of herself playfully "squeezing" Pedro Pascal's eyes out. The photo was teasing Pascal's character's, Oberyn Martell, death.

The "stone heart" could mean the appearance of zombie Catelyn, but fans will have to watch the season final on Sunday to find out. Weiss and David Beinoff have teased it is the biggest season finale in "Game of Thrones" history.

"It's the best finale we've ever done, bar none," Benioff and Weiss said in a statement. "The performances from our cast, the direction from Alex Graves, the VFX work, the new [music] cues from Ramin Djawadi-all of it came together in perhaps the finest hour we've produced. We're immensely proud of 'The Children.' And a little intimidated by the episode, because now we have to get back to the business of season five and figure out a way to top it."