How Arya's major moment at the Battle of Winterfell was foreshadowed last season

The Battle of Winterfell on season eight, episode three of "Game of Thrones," titled "The Long Night," came to a surprising end when Arya sneak-attacked the Night King and stabbed him with her Valyrian steel dagger.

Though this was a twist many fans might not have seen coming, the HBO drama's showrunners David Benioff and D.B. Weiss planted one major clue back on the seventh season of the series.

The Game of Thrones co-creators have had this Arya plan in mind for three years

Bran Stark Isaac Hempstead Wright Game of Thrones season eight episode three The Long Night Helen Sloan HBO

In HBO's "Inside the Episode" segment, showrunner David Benioff says they've known for about three years that Arya would be the one to kill the Night King.

"We hoped to kind of avoid the expected," Benioff said. "Jon Snow has always been the hero, the one who's been the savior, but it just didn't seem right to us for this moment."

Depending on when they filmed that behind-the-scenes video, it's safe to assume the plan has been for Arya to kill the Night King since at least the time season seven was in production back in late 2016 (the seventh season aired in the summer of 2017).

"We knew it had to be Valyrian steel, to the exact spot where the Child of the Forest put the blade to create the Night King," Benioff continued. "And he's uncreated by the Valyrian steel."

Only a handful of characters on "Game of Thrones" have Valyrian steel swords, but it seems as if Benioff and Weiss decided to get the "Catspaw dagger" back into Arya's hands on season seven in order to stage her assassination of the Night King.

Ever since the sixth season, the showrunners have been giving the cast cryptic directions for certain scenes

Entertainment Weekly's James Hibberd interviewed showrunners David Benioff and D.B. Weiss while on the set for season six. In his report of the visit , Hibberd wrote that Benioff and Weiss already knew the planned ending for the show at that point, even though the cast had no idea what was coming.

D.B. Weiss, Dave Benioff, Game of Thrones Jamie McCarthy/Getty Images

"Sometimes they gave actors cryptic suggestions when filming certain scenes, with those final episodes in mind," Hibberd said. "The actor didn't know why they were doing something a certain way, only that it was somehow important."

We're quite certain that a scene between Arya and Bran on the seventh season was one of these moments, especially given what we know now about the Valyrian steel dagger.

Bran Starks greensight and the Valyrian steel dagger

When Arya and Bran reunited on the seventh season of "Game of Thrones," he had just been given the Valyrian dagger by Littlefinger. Bran in turn handed it over to Arya, telling her he had no use for it. But he has a strange expression on his face as she takes it, almost as if he's puzzling over a somber thought.

The moment was notable to us back when it first aired , though at the time we only dared guess Arya night would use it on a White Walker.

Game of Thrones Bran and Arya season 7 HBO

INSIDER spoke with Isaac Hempstead Wright about this scene after the seventh season finale, and he said that moment was supposed to be played for a greater importance.

Hempstead Wright said Bran is able to get "an idea of destiny" or "fate," and we brought up the moment when he handed Arya the Valyrian blade. She would later use it to kill Littlefinger on the seventh season finale.

"You know that's interesting because that is exactly ... I was trying to play that," he said. "I'm really glad that came through. When Bran's looking at that dagger, I was thinking that he's feeling the Valyrian steel and thinking, 'I can see where this dagger's going to end up. It's going to be used to kill Littlefinger.'"

The actors only get one season's worth of scripts at a time, so when we spoke with Hempstead Wright he had no idea that Arya would also use that dagger to eliminate the Night King and therefore the entire Army of the Dead. But Hempstead Wright's certainty of what he was conveying in that scene sounds just like the kind of "cryptic" hint Benioff and Weiss might have been trying to convey.

Bran Stark Godswood Valyrian Steel dagger Game of Thrones HBO

"I don't know if Bran knows it there yet, but as he looks at it and touches it, it's becoming clear that this is important," Hempstead Wright said. "And that's why he gives it to Arya so suddenly. He's thinking, 'I don't know why, but you need this dagger.'"

Melisandres prophecy given to Arya on the third season

In addition to this seventh season foreshadowing of Arya's fate, Benioff and Weiss may had help from two earlier scenes that laid the groundwork for Arya Stark doingsomething important on the final season of the series.

To get the most obvious out the way first, let's revisit what Melisandre said to Arya back on the third season of "Game of Thrones."

Melisandre and Arya Game of Thrones HBO

As Arya and Melisandre helpfully recapped for viewers in the middle of the battle, they met back on season three when Arya was in the Riverlands with the Brotherhood Without Banners. Melisandre had come to take Gendry back to Dragonstone for her creepy bloodmagic ritual and Arya added the red priestess to her kill list.

"I see a darkness in you," Melisandre told Arya when confronted by the young Stark girl. "And in that darkness, eyes staring back at me. Brown eyes, blue eyes, green eyes, eyes you'll shut forever. We will meet again."

Melisandre's track record with prophecy on the show has been wobbly (which reminds us, where does the Night King's death leave the Prince or Princess That Was Promised prophecy ?) but this scene stood out to many fans. The third season of "Game of Thrones" was still closely tracking George R.R. Martin's books, but this scene was a total invention on Benioff and Weiss' behalf.

Anytime the showrunners seemed to go out of their way to insert a new side-story or scene, fans took note.

game of thrones arya season 4 Helen Sloan/courtesy of HBO

As Arya progressed in her assassination skills and went to Braavos to become a Faceless Man, it was easy to assume Melisandre's words were simply a prediction of the many people we saw Arya kill. It's possible Benioff and Weiss decided upon the Night King's fate and realized they could use Melisandre and that scene to tie in Arya's big battle-ending moment.

What is next for both Arya and Game of Thrones?

The Night King was never on Arya's iconic kill-list, given she just learned of his existence a short while ago. But Cersei Lannister is still alive in King's Landing, and Arya may set her sights on her next.

The teaser for episode four of "Game of Thrones" shows Daenerys Targaryen and the Northern forces celebrating the victory at Winterfell, and planning for "the last war" against Cersei in King's Landing. Arya will presumably be part of the contingency who sails south, which means she's in the perfect position for crossing Cersei off her list.

As for "Game of Thrones" itself, fans are finding themselves surprised to see the Night King and Army of the Dead dispatched with just halfway through the final six episodes. We still have three more episodes to go, which leaves a lot of time for twists and turns. Can the show top Arya Stark surprise-killing the Night King? We'll know within three short weeks.