An unanswered question about Westeros’s past could be the key to really understanding the metaphor everyone assumes the HBO epic is founded upon.

I hope that someday I find out what happened to Valyria.

There are a lot of other lingering mysteries left in Game of Thrones, the HBO adaptation of George R.R. Martin’s A Song of Ice and Fire. At this point, the show is just trying to end—to surmount the nearly impossible challenge left by Martin’s unfinished book series, and attempt to sew up the fight for control of Westeros in six super-sized episodes. I would not be surprised if the TV show concluded without trying to explain or understand what is, essentially, one of its many, many footnotes like the story of Valyria—the ancient city whose terrible destruction permanently altered the world of Westeros. Valyria used to be the capital of the world; its Doom was as if the fall of Rome happened in a one-day conflagration. The show’s referenced the Doom of Valyria as far back as Season 2, when it was first mentioned by the mysterious masked character Quaithe. One of the ways in which Martin’s books, and HBO’s show, subverts expectations is by placing its action after the great events that defined their time — the Doom of Valyria, Robert’s Rebellion (and Rhaegar’s defeat at the Trident), the building of the Wall. The characters in the world of Westeros, like us, live in the shadow of a vast history formed by the actions of others.

Martin’s sprawling epic—as interpreted by Game of Thrones creators David Benioff and D.B. Weiss—has undercut nearly every route towards a narrative resolution, which has made it both engaging and maddening. Now the show has cast its attention toward the invading White Walkers, who are taking advantage of a long winter by marauding over the Wall and into the world of humans, converting the citizenry into ice zombies as they go. This feared phenomenon could be another Long Night, and it’s one that requires collective action within Westeros.