A Light in the Gloam

The flame on the hill has burned since before the town had a name.

It is not fire. It is the idea of fire, it has to be fed, and feeding it is what the Lanternguard is actually for.

Eleven days ago your mother went down into the Deepworks to feed it, with the Princess walking behind her as witness. Nobody came back up. The flame is down a hand's width, which it has never done before. And a man who stands where no light touches him has put an offer to the King: he has the Captain and the Princess, they are both alive, and he gives them back on the day Hearthold lets the flame go out.