"Game of Thrones" director Alex Graves explained why a major character did not return to the series in the season four finale.

In an interview with Entertainment Weekly, Graves explained the showrunners never included Catelyn Stark's zombified persona Lady Stoneheart in the last episode of the season. Book readers were expecting to see her in the last scene, but were let down when the show ended with Arya Stark on a ship to Braavos.

"It's a great question, because it's all I asked about last year when I was doing [the episode with Brotherhood Without Banners leader] Beric Dondarrion - who ultimately is the person who finds Catelyn and turns her into Lady Stoneheart. But no, they didn't do it. It was never on the docket to do this season - ever," Graves told EW.

"They [showrunners David Benioff and Dan Weiss] have such a challenge adapting the books into a really focused television experience. It's very hard, it's very complicated, it's much harder then they've been given credit for, I think - and they do a brilliant job."

Graves doesn't know if the showrunners will include Lady Stoneheart in the series. Even if she does appear, the director is insure what zombie Catelyn Stark will add to show, considering her new persona randomly kills people and shows no mercy.

"But to bring back Michelle Fairley, one of the greatest actresses around, to be a zombie for a little while - and just kill people? It is really sort of, what are we doing with that? How does it play into the whole story in a way that we're really going to like? It just didn't end up being a part of what was going to happen this season," Graves explained to EW.

"And finally one [more] reason: In case you didn't notice, a lot happens this season ... To add that in is something they opted out of. But what's funny is that it was never going to be in the season, yet it took off on the Internet like it was going to happen."