Melisandre may have dipped out early in Game of Thrones season seven, but her last conversation before disappearing across the Narrow Sea may hold an incredibly important clue that could turn the tides of Jon and Daenerys' war efforts in season eight.
After making sure Daenerys invited Jon Snow to Dragonstone, Mel rightfully steered clear of the King in the North as he prepared to meet the dragon queen. When Varys approached her on the island's most dramatic brooding cliff, she revealed two things: She is leaving for Volantis but will soon return to Westeros, where she has foreseen her own death. Why would the red priestess want to go to Volantis? More importantly, why the heck would she return to Westeros? The answer to both of these questions lies in the history of Volantis, and a blink-and-you'll-miss-it scene from season six.
Volantis, one of the Free Cities of Essos, is notable for two things: it sits on an absolute butt-ton of dragonglass, enough to encircle the city in a 200-foot wall of pure obsidian, and it's home to the single largest temple of R'hllor in the world. The Red Temple of Volantis is occupied by hundreds of priests, priestesses, and attendants, but more importantly, it has its own army of one thousand ferocious soldiers called the Fiery Hand, who wear dark red armor, orange robes, and wield spears shaped like flames—it's possible they even light their weapons on fire like R'hllor acolytes Thoros of Myr and Beric Dondarrion. The Fiery Hand is specifically controlled by the High Priestess of the Temple of Volantis, and they answer to no one else.
Eagle-eyed viewers will recall that the High Priestess of Volantis has already made an appearance on the show. Tyrion invited Kinvara, the current High Priestess, to Meereen in season six to discuss the spread of pro-Daenerys propaganda in the guise of religion, only to discover that Kinvara was already very much riding the Dany bandwagon:
Tyrion: "The truth is, we need your help. We were hoping that we could somehow persuade you..."
Kinvara: "You don't need to persuade me. I came to help. Daenerys Stormborn is the one who was promised. From the fire she was reborn to remake the world...Daenerys has been sent to lead the people against the darkness in this war and in the Great War still to come."
This was the last time viewers saw Kinvara, but since she left she's likely been keeping the promise she made to aid Daenerys in any way she can with all the power of her order. When Melisandre arrives in Volantis, it will only make sense to make a beeline for the Red God's powerful Lady-Pope and give her the update on the Great War's progress.
Then again, it would be surprising that a priestess with Kinvara's status wouldn't already know what the Great War is underway, so it's possible that Melisandre will walk right into the Volantene Temple's war prep zone and be the final catalyst they need to load up the Fiery Hand and sail across the narrow sea to bolster Dany and Jon's forces against the Night King.
Can you just picture a thousand zealot soldiers in bright orange robes marching across the frozen north with flaming spears? Now imagine that army has a weapon cache created entirely from dragonglass, which is so common to them they use it to build houses? Even Davos would be happy to see Melisandre if she showed up with that boss level of backup at just the right moment. Of course, as awesome as it sounds, it's juuust a theory until season eight proves it right or wrong. Sigh. And now our watch begins...