Gilly's nighttime reading on 'Game of Thrones' may have just changed everything

Sometimes, Game of Thrones characters spend years chasing mysteries, risking life and limb to dig up secrets that have the potential to shake up the entire playing board as we know it.

And then other times, they casually stumble across them while enjoying a bit of light bedtime reading.

In this week's episode of Game of Thrones, Gilly unearths a bombshell with potentially life-changing consequences for Dany, Jon ... and the entirety of the Seven Kingdoms, really.

While paging through the records of the former High Septon Maynard, Gilly asks Sam about a word she doesn't understand. "What's annulment?"

Sam answers, "It's when a man sets aside his lawful wife."

"Maynard says here that he issued an annulment for a Prince 'Raggar' and remarried him to someone else at the same time in a secret ceremony in Dorne," says Gilly.

Assuming "Raggar" is actually Rhaegar Targaryen, this is huge. We already know that "R + L = J" – that is, that Jon's true parents are Rhaegar and Lyanna Stark. What Gilly may have revealed is that Jon isn't the bastard son of Rhaegar and Lyanna. It seems he's Rhaegar's legitimate, lawful son.

Which, in turn, means Jon has a better claim to the Iron Throne than Dany does.

This reveal derails all of Dany's plans to conquer the Seven Kingdoms, since her claim is wholly based in being the only living relative of the last Targaryen king, Aerys II. (Well, that, and "I have dragons, so bend the knee or get burned to death.")

It positions Jon against Dany and Cersei as a contender for the Iron Throne. It upends the dynamic of his fragile alliance with Dany, and therefore their battle against the White Walkers. Depending on how Jon and Dany (and anyone else who hears about it) takes this news, it changes everything.

... Or it would, if either Sam or Gilly had any inkling of what it meant. Instead, Sam, who's already cranky that he's wasting away his time copying records at the Citadel instead of researching ways to battle the White Walkers, interrupts Gilly with a temper tantrum and then stalks out of the room.

Later, he and Gilly pack up their things to leave the Citadel – all 15,782 steps of it. "I'm tired of reading about the achievements of better men," sighs Sam.

Oh, Sam. A better man would have listened to his girlfriend instead of whining at her, and learned something crucially important in the process.