Showrunners David Benioff and Dan Weiss break their silence on why the fan-favourite character from the book series didn't make the cut to the small screen. *Spoiler alert for George R. R. Martin's fantasy series below*

In George R. R. Martin's book series 'A Song of Ice and Fire', following the actions of the Red Wedding - arguably one of the most shocking moments to play out in TV history - Catelyn Stark finds a way of coming back. The character, played by Michelle Fairley, is re-introduced to us in 'A Storm of Swords', but looking and acting very different. Gone is Catelyn Stark, and in her replacement is Lady Stoneheart, who leads the Brotherhood without Banners.

The re-introduction of a character that ultimately goes from being a mother and all-round fighter for her Stark family, to an undead villain hellbent on murder is quite something. She only appears twice in the book series, but both moments are very memorable. With two more books still on the way from Martin, her fate in the concluding novels is unknown. And unfortunately, the character never made it into Benioff and Weiss' series. But the reasons why have now been explained.

In the upcoming tell-all book 'Fire Cannot Kill A Dragon', which features behind-the-scenes moments from years of shooting the fantasy epic, the showrunners have given reasons - three in fact - as to why Lady Stoneheart was absent after Catelyn Stark's death.

The first is that Martin didn't want to reveal what the character would be getting up to in the remainder of the books - but hey, they could have adapted her storyline like they had presumedly done for the rest of the characters (Daenerys Targaryen, we're looking at you).

Secondly, the resurrection of the character could have weakened Jon Snow's revival later in the series - which we can understand. Benioff says: "Too many resurrections start to diminish the impact of characters dying. We wanted to keep our powder dry for that."

The final reason why Lady Stoneheart was absent is that the showrunners felt that Catelyn's exit from the show was one of the best ways for the character to bow out. "Catelyn’s last moment was so fantastic, and Michelle is such a great actress, to bring her back as a zombie who doesn’t speak felt like diminishing returns," Benioff explains.

So, there you have it. Now we are even more invested in what Stoneheart has in store for us in Martin's final entries in the book series 'The Winds of Winter' and 'A Dream of Spring'.

Via Entertainment Weekly.