The most eagle-eyed Game of Thrones fans knew Gendry would make his return during Season 7's fifth episode "Eastwatch" before he even hit the screen. Joe Dempsie's name popped up in the opening credits and we knew then that all of Gendry's rowing eventually landed him somewhere. It turns out he's been hiding in Flea Bottom, right under Cersei's nose. He buzzed his hair and promptly took up blacksmithing again, patiently waiting for adventure to call. But one fan theory may pack in more action than he's bargained for: the theory that Gendry is Azor Ahai on Game of Thrones.
Azor Ahai is the legendary prince who saved the Seven Kingdoms from White Walkers the first time around, thousands of years ago, with the help of a flaming sword named Lightbringer. The Prince Who Was Promised, of Melisandre's prophecy, is generally thought of to be some kind of reincarnation of Azor Ahai, and, for the sake of the television series, this will probably be the case, since introducing a long-dead prince as a new character seems unlikely at this point. The only clues we have about The Prince That Was Promised come from two prophecies in the books.
They prophecies state that:
There will come a day after a long summer when the stars bleed and the cold breath of darkness falls heavy on the world. In this dread hour a warrior shall draw from the fire a burning sword. And that sword shall be Lightbringer, the Red Sword of Heroes, and he who clasps it shall be Azor Ahai come again, and the darkness shall flee before him.
But it doesn't stop there:
When the red star bleeds and the darkness gathers, Azor Ahai shall be born again amidst smoke and salt to wake dragons out of stone.
These are the passages by which fans have been measuring up possible Azor Ahai candidates. This handy spreadsheet devised by Redditor Alutic actually breaks down several of the characters by which pieces of the prophecy they fulfill (including Hot Pie, so, who knows!). According to that chart, Gendry only fits the "born amidst salt" piece so far. The giant literal clue, of course, is that Azor Ahai has to forge another Lightbringer to fight the White Walkers, and it was a very difficult process the first time around. It took three tries and was only successful once he drove it through his beloved wife's heart, imbuing the sword with magic.
Gendry is the only character around with the skill to literally forge swords, and probably tricky magical ones at that. Of course, many think Lightbringer could be a metaphorical weapon as well, since Daenerys and Jon Snow are the most popular candidates for Azor Ahai.
Hopefully, Gendry survives his adventure north of The Wall because, even if he isn't The Prince That Was Promised, having a blacksmith around who can forge dragonglass weapons would be pretty cool right now.