"I have to die in this strange country, just like you." Those with Melisandre's parting line to Varys as she left Dragonstone last season, heading back across the Narrow Sea to Essos, where none of our story will take place next season. Will Melisandre be in Game Of Thrones Season 8? With only six more episodes to go, that means the show needs a way to bring her back quickly, and send her directly Northwards, especially if she'd going to be dying in the "strange" country of Westeros before the show ends.
So why would Melisandre come back? It seems almost counter intuitive that she would, since coming back means she will most likely run right into the Character Formerly Known as Jon Snow, Real Westerosi Hero™, and he's vowed to kill her if he saw her again, and so forth. (Very awkward.) But since she has seen her fate is to be a part of this final battle, and most likely to die in it, it must be a very serious thing that causes her to come back. Does R'hllor command her to go? Does her order insist she return?
Or does she have something that Jon and Dany need to help them win the battle and kill the Night King?
That's where our newest theory comes into play. Devised by a Redditor, it takes details from the last book that George R.R. Martin has published and attempts to extrapolate some of the plot points he's introduced in the novel into coming into play in the final battle. We're talking of course, about all those armies-for-rent currently camped out around the walls of Meereen.
For those who haven't read the novels, that's actually where Tyrion is currently in his storyline. He's not made it into Meereen to see Dany. (He won't make it in until after she jets either.) He's currently fighting with the Second Sons. While he's basically drunkenly bumming around Essos, he hears about a group known as the Fiery Hand, which are in Volantis -- right where Melisandre is headed.
The Fiery Hand are the slave soldier guards who defend the temple of the Lord of the Light. There's exactly 1,000 of them (it's a long story) but they are a bit like the Unsullied, in that they are some of the most feared warriors in the world.
The theory goes then that Melisandre is going to go back to her main temple and tell Kinvara (who we met in Season 6) that Daenerys and/or Jon Snow are the Prince(ss) that was Promised. If they're really going around preaching in the name of the Mother of Dragons, what they really need to do is send an army to help them fight the Great Extinguisher of Light, the Night King, over on that other continent.
Whether or not Kinvara will take a lot of convincing to listen to Melsiandre is not clear. One would think after Melisandre's screw up with Stannis, her peers aren't going to be inclined to listen. But since they've all already been preaching about Daenerys, maybe it will be more like, "What took you so long? We figured this out ages ago."
But who knows? Maybe R'hllor himself needs to get involved, commanding his followers to hand Melisandre an army. Maybe Melisandre will arrive and find Kinvara will have the Fiery Hand all packed up with their little suitcases and one way tickets to Westeros, ready to go.
Either way, we're not sure the show will even want to dedicate screen time to all this -- maybe Melisandre will just pull a Sansa-and-Littlefinger and ride over the ridge with the Fiery Hand, Gandalf-style, just as all hope looks to be lost. Either way, we're just certain we're not done with her yet.