For years, fans have been wondering about what happened to Gendry on Game Of Thrones after he rowed away from Dragonstone way back in the Season 3 finale, "Mhysa." If reports are to be believed, a solution to that lingering mystery is finally about to be provided when Gendry makes his triumphant return to Game Of Thrones Season 7. It may not be known exactly when the character will come back, or under what circumstances, or where he will have been during the intervening years… but ultimately those questions don't matter as much as the question of what purpose he will serve in the story moving forward.
Yes, viewers will undoubtedly be curious about whether King Robert's handsome bastard returned to Flea Bottom, or joined up with the Brotherhood Without Banners, or has just been rowing around in circles for the past four years. But if the writers really are planning to bring the character back, then they must have a reason for it beyond tying up a minor loose end.
Most theories about Gendry's role in the saga's conclusion involve his Baratheon lineage. Given that he's the only remaining offspring of Robert, Gendry may have a better claim to the Iron Throne than the late king's wife, even given his status as a bastard. As such, he could be a key figure in destabilizing Queen Cersei's rule, and Gendry could even end up on the Iron Throne himself — either as a solo sovereign, or alongside Daenerys Targaryen, allying their rival houses through marriage.
But it's just as, if not more, likely that Gendry's purpose will involve another defining aspect of his character; not his noble father, but his chosen profession. Gendry's royal blood already played a role in Season 3 with Melisandre's magic, and now it's time for the bastard's skills as a blacksmith to be put to good use.
There are a couple of clues that Gendry's abilities as a smith will come in handy somewhere down the road. In the final Season 7 trailer, Jon Snow can be heard speaking to someone whose family fought alongside his own "for centuries." The Starks' closest allies have always been the Baratheons — and as the sole Baratheon left alive, Jon could only be talking to Gendry. But Jon is utterly unconcerned with the squabbles over the Iron Throne; he's much more worried about the battle against the White Walkers, and Gendry's parentage will likely not have much impact on the outcome of that conflict. His smithing skills, however, could have a huge impact.
In the Season 7 premiere, Sam learned that the island of Dragonstone is essentially a giant mountain made out of dragonglass — and dragonglass, of course, is one of only two substances known to be able to kill White Walkers. This knowledge is part of the reason that Jon decided to accept Dany's invitation to come to Dragonstone: so he could scope out the dragonglass situation for his use in the upcoming war. But what's the King in the North going to do with a giant supply of raw stone? Won't he need someone to forge it into weapons?
…Enter Gendry. As an apprentice, he worked under Tobho Mott, perhaps the greatest blacksmith in King's Landing. If Jon were to find himself suddenly in the possession of massive amounts of uncut dragonglass, what better time for Gendry to make his long-awaited reappearance? And dragonglass might not be the only material the bastard is adept at working with. Although this was never explicitly stated on the show, when Tywin wanted Ned's Valyrian steel greatsword Ice reforged in the books, he hired Gendry's master Tobho Mott to do the work.
Along with dragonglass, Valyrian steel is the only other substance that can kill a White Walker. With so few Valyrian steel swords left in the world, perhaps Jon will want some of them melted down in order to infuse more weapons with the magical material. And who better to do that work than Tobho Mott's apprentice? Gendry might even be able to make himself a tool that comes in handy during the upcoming war. King Robert's weapon of choice was always a war hammer; how awesome would it be to see his son charging into battle against the White Walkers swinging a massive hammer infused with Valyrian steel and dragonglass?
It should please Gendry fans to know that, after so much time offscreen, the handsome bastard just might end up being the key that helps Jon Snow win the war for Westeros.