The fog over the Foggy Isles never lifts, and it is not weather. It is a made thing, a standing working held in place by the Veilkeepers, the order that holds the islands and sells the one service the fog is good for. The isles themselves are unremarkable: a scatter of low, wooded islands in the northern Shattered Sea, close enough to Phyndarr Sound that the mist drifts into the channel's eastern edge and unnerves the crews passing through. What matters is that no one outside the order can find a way through the veil, and the order intends to keep it that way.
Sanctuary
People come to the Foggy Isles to stop being found. A lord on the losing end of a succession. A factor who has emptied the wrong strongbox. A deserter, a spy whose face is now known on three coasts, a witness someone powerful would rather bury. The isles take all of them on the same terms and ask nothing about which side they ran from. Neutrality is the whole product. A refuge that turned anyone away over their politics would be picking a side, and a refuge that picks sides is just a faction with a coastline.
Shelter is neither free nor cheap. A guest pays once in coin or goods or labor, and once in truth: a single real secret, surrendered to a Veilkeeper at the edge of the fog, kept as the price of being let in. The order calls it a keeping, and what it does with the keepings is its own long story, told in the Veilkeepers' own entry. Here it is enough to say that the coin buys the room and the secret buys the peace.
The peace
Inside the veil there are no guards in the ordinary sense, because the Veilkeepers do not need them. They hold two things every guest fears more than a blade. The first is the way out. A guest who makes trouble is put into a boat and rowed into the fog by a keeper, who steps off onto a second boat partway and leaves the troublemaker to find open water alone, which no one does. The second is the keeping. Break the peace and the truth surrendered at the veil travels to the one person it would ruin you to have hear it. Between the fog and the keeping, the Foggy Isles are the calmest violent place in the Western Isles. Enemies who would knife each other anywhere else share a table here with their hands kept visible, because both have more to lose from the keepers than from one another.
You may bring your name in or leave it at the water. You may not bring it in and keep it. The fog is not for people who still want to be someone. — a keeper's greeting at the edge of the veil
Tarkhon names the isles a problem it means to solve, the way it names Tollgate at the mouth of the Sound a problem. It has solved neither. A fortified island can at least be seen to be besieged. The fog cannot be fought, and the secrets the keepers hold over half the courts of the region, Tarkhon's own included, make the isles safer the louder the empire grumbles.