Game of Thrones is gearing up for its belated, truncated Season 7 premiere this July and at the forefront of viewers' minds since pretty much immediately after the Red Wedding is whether or not Catelyn Stark will return as the silent, resurrected Lady Stoneheart to avenge the Starks once and for all. Season 6 seemed like it was gearing up for her introduction, what with all the time spent in the Riverlands and the constant references to Catelyn. But the season ended without a trace of her. So will Lady Stoneheart be in Game of Thrones Season 7? Everyone involved is awfully insistent about the answer being no (which has been a trap before!).
In the books, Catelyn is resurrected by Beric Dondarrion, who sacrifices his own life to bring her back, bearing a scar across her neck from her throat-slitting and pale, brittle skin. She also can't speak. Lady Stoneheart becomes the de facto leader of the Brotherhood Without Banners in Beric's absence, and embarks upon a vicious killing spree to avenge her family. The first hint that we won't see Catelyn return is the fact that Beric is still alive and well on the show, which means she can't be, since a sacrifice is required to resurrect someone.
But also, various members of the production team have insisted that Lady Stoneheart is not going to be a thing on the TV series at any time, since the show has veered into uncharted territory, surpassing the timeline of the books. Last year, George R.R. Martin admitted that the character had been cut from the show and that he was too busy trying to finish the books, otherwise he would have been more involved with the HBO series and found a way to include her.
Then, Game of Thrones director Mike Mylod also chimed in on Lady Stoneheart during an interview with IGN, and stated:
I can honestly say, hand over heart, that I have not had one discussion about Lady Stoneheart. So I have no idea what's going on in David and Dan's minds...I've genuinely had no discussions about Lady Stoneheart, so I genuinely couldn't comment about whether that might or might not be in their minds for the future.
As for showrunners D.B. Weiss and David Benioff, they've given predictably non-response responses to the question, but even if they did tell us Lady Stoneheart was a casualty of the on-screen adaptation, they've flat-out lied to us before (see: Jon Snow's return), so it's not like that would mean much. At this point, our only hope of finding out the truth is to watch and see how these final two seasons play out.