But the phrase also takes on a literal quality in the show, because characters in Game of Thrones have been known to come back from the dead. After the brothers of the Night's Watch stabbed him, Jon Snow (Kit Harington) was resurrected by Melisandre (Carice van Houten). Similarly, Beric Dondarrion (Richard Dormer) of the Brotherhood Without Banners has been raised from the dead multiple times by the same God of Light Melisandre serves.
While Beric and Jon's storylines figure heavily in HBO's Game of Thrones, there's one iconic (and undead) character in George R. R. Martin's A Song of Ice and Fire trilogy who has yet to appear in the HBO show: Lady Stoneheart, the resurrected version of Catelyn Stark (Michelle Fairley). Will Lady Stoneheart appear in the final six episodes of Game of Thrones? Fans aren't ruling it out — because it would be a major game-changer. In fact, Lady Stoneheart's reappearance may even herald Brianne's (Gwendoline Christie) death.
Who is Lady Stoneheart?
She was once called Catelyn Stark; now, she's a stone-cold killer. Her nicknames are "the Hangwoman," "the Silent Sister," and "Mother Merciless." She's a bandit, hunting down those who wronged her with the help of a troop of brawny men.
How did Catelyn Stark become Lady Stoneheart?
Her origin story begins at one of the most traumatic events in Game of Thrones history: the Red Wedding. Along with her son Robb Stark and 3,500 Stark bannermen, Catelyn Stark is killed at her brother's wedding feast at the Frey castle. The event has enormous consequences for the Stark family, strategically and emotionally.
In the A Song of Ice and Fire book series, Catelyn's story continues. After the massacre, Catelyn's body is dumped in the river. Arya's long-lost wolf Nymeria sniffs out Catelyn's body a few days later and pulls her from the water (Starks helping Starks out).
Enter the Brotherhood Without Banners, a roving troop of soldiers and nobles led by the Lightning Lord, Beric Dondarrion. Originally, they were organized by Lord Eddard Stark to hunt down Gregor Clegane for atrocities committed against the people of the Riverland. They broadened their mission to protect smallfolk against all potential predators, like northern raiders and outlaws.
The Brotherhood Without Banners also has a supernatural twist: Beric was stabbed to death. Then, the Red Priest Thoros of Myr accidentally resurrected him, giving Beric the power to come back from the dead.
So, the Brotherhood Without Banners comes across Catelyn's body. Beric chooses to give Catelyn the "kiss of life." By raising her back to life, he sacrifices himself in the process.
Why did Beric sacrifice himself for Catelyn?
It's a question that has been pored over. Earlier, Beric had expressed being tired of coming back from the dead: "Six times is too many." Perhaps he revived Catelyn because he was ready for a true death. Or perhaps he felt like he still owed the long-dead Eddard Stark something since he hadn't caught Ser Gregor Clegane. Or, perhaps he revived Catelyn to fulfill his promise to Arya that he'd reunite her with her mother. Either way, he gave Catelyn the "last kiss" and unleashed Lady Stoneheart.
What does Lady Stoneheart look like?
She's sort of a mess. Since Catelyn's throat had been slit at her death, Lady Stoneheart must close the wound with her hand when she tries to speak. Even then, her voice is no louder than a rasp. Her wounds aren't entirely healed, but she's a killer.
How does Lady Stoneheart spend her days?
Lady Stoneheart has nothing of Catelyn's mercy or kindness. Together, she and the Brotherhood Without Banners maraud the countryside and slaughter anyone associated with the Red Wedding — that includes anyone even associated with the Freys, Boltons, or Lannisters.
Where does Brienne come into this?
In A Song of Ice and Fire books, Lady Stoneheart is Brienne's primary antagonist. Lady Stoneheart and the Brotherhood Without Banners come across Brienne, her former protector, who now carries a Lannister sword. Lady Stoneheart interprets this as a betrayal. She gives Brienne a choice: kill Jaime or die herself. Brienne refuses to kill Jaime.
So — get this! Stoneheart has Brienne and Podrick killed! Twist!
Where might Lady Stoneheart fit into season 8?
George R. R. Martin expressed regret over Lady Stoneheart's absence from Game of Thrones. “That was probably the first major diversion of the show from the books and, you know, I argued against that, and [creators] David [Benioff] and Dan [Weiss] made that decision,” Martin said in Time.
At this point, Game of Thrones exists in a different universe than ASOIAF, especially where Lady Stoneheart's storyline is concerned. Beric is with Tormund Giantsbane at the Wall, fate unknown (trailers suggest Tormund, at least, lives). Brienne is alive.
But who knows? Maybe, somewhere in Westeros, Lady Stoneheart is out there staging The Walking Dead.