Game of Thrones season 4 will likely feature a mysterious new character called Lady Stoneheart, and she may just so happen to be a presumed dead character.
Game of Thrones fans who were upset about the death of Catelyn Stark (Michelle Fairley) in the "Red Wedding" episode of season 3 may see her exact her revenge on the Lannisters and the Freys in season 4. Assuming the Game of Thrones writers adapt the plot development for season 4, as is featured in George R. R. Martin's novels on which the series is based, fans will witness the triumphant return of Catelyn Stark in the form of Lady Stoneheart.
In A Storm of Swords, the third book in the novel series, the Freys thrown Catelyn's body into the river after the Red Wedding. Nymeria, the direwolf of Arya (Maisie Williams), drags Catelyn's body out of the river and her body is found by the Brotherhood Without Banners. The Brotherhood's leader, Beric Dondarrion (Richard Dormer), uses his powers of resurrection to bring Catelyn back to life.
Catelyn is revived and takes on the new name of Lady Stoneheart. She becomes the new leader of the Brotherhood Without Banners and goes on the hunt for every possible Lannister and Frey they stumble upon.
After Catelyn's death, Fairley told reporters that her character was really dead, suggesting that it was the end of her run on the show. Though she could be using misdirection to not spoil the surprise, it's possible that Game of Thrones may use another actress to play Lady Stoneheart, considering her appearance drastically changes after being dead.
Season 4 of Game of Thrones is set to premiere in spring 2014 on HBO, though a specific premiere date has not yet been scheduled by the network.