Warning! Spoilers for Game of Thrones Season 8 lie ahead!
There are only four episodes of Game of Thrones left, but there are clearly still many secrets to reveal. So far this season, we have seen both Jon Snow and Daenerys grapple with the reality that Jon is a Targaryen — the trueborn son of Rhaegar Targaryen and Lyanna Stark. Now, some fans are taking it further, suggesting that Rhaegar became the Night King.
Hardcore fans of both the show and it source material novel series, A Song of Ice and Fire, love to speculate about Rhaegar. For a dead man that we never really see, he factors heavily into the story, and some suggest he still does. As a refresher, Rhaegar was Daenerys' older brother who was killed by Robert Baratheon at the Battle of the Trident, thus allowing him to take the throne.
According to what we've heard, Robert caved in Rhaegar's chest with his war hammer, scattering the rubies adorning his armor everywhere and ending the war. However, in a fan theory summed up by Reddit user TryinToBeHappy, that wasn't the end. Fans point out that Rhaegar spent a lot of time at Dragonstone, where we now know there was a massive supply of Dragonglass. We also know that Rhaegar was interested in magic, prophecy and "the higher mysteries."
They suggest that Rhaegar's armor was actually studded with dragonglass, not rubies — perhaps painted red or stained with his blood, leading to the confusion. From there, they speculate that Robert's final blow could have lodged the dragonglass into Rhaegar's chest, and through some confluence of magic, turned him into the Night King.
That's only the how. Fans have put forth many reasons why they believe this makes sense. For starters, Rhaegar was able to ride Daenerys' dragon Viserion once he was dead, suggesting some ties to the blood of dragon riders.
Another point raised in favor of this theory is the fact that Daenerys and Jon Snow are still alive. Between the battle at Hardhome and the battle on the frozen lake, there were several times when it looked like the Night King could have taken down these leaders easily — especially now that we know he can throw a spear like it's launched from a cannon. Fans speculate that the Night King did not kill Jon and Daenerys because they are his family.
Finally, the last small piece of evidence worth noting here is that there is a precedent for Targaryens searching for magic and knowledge north of the Wall. While it is not mentioned in the show, the Three-Eyed Raven who teaches Bran is supposed to be Brynden Rivers, also known as Bloodraven, a Targaryen bastard banished from the Seven Kingdoms generations ago, kept alive by the magic of Wierwood trees.
In addition, George R.R. Martin's latest book, Fire and Blood, tells of a few instances when Targaryens visited the North and found strange interactions between their dragons and the magic of the old gods. Whether Rhaegar is the Night King or not, there is certainly a powerful connection between the magic of ice and fire that has yet to be uncovered.
Supporters of this theory say that the zombified Rhaegar is marching south with a vague memory of his days as a royal heir. They believe he is not motivated by a will to destroy all life, but a simply urge to take back his rightful throne. Of course, this was contradicted last week when Bran said that the Night King's goal was to erase all life, but this theory is not exactly out of the running yet.
Game of Thrones airs on Sundays at 9 p.m. ET on HBO.