Beyond the shores of Lake Hali in Hyades, stands the ruins of a once promising land, a shattered mockery of what was once Carcosa. Now, twisted denizens roam the streets, crowding the gates and thieving from any stray travellers that manage to find themselves so lost as to find these shores. The unfortunate souls that manage to make it through the gates see that the city stands mostly empty, doors barred, windows shuttered, and no being walks the streets. For here in Carcosa, He Who is King reigns supreme. The Byakhee fly through the twilight skies, hunting those who show themselves, the Harlequins roam the streets looking for those that might fit in their strange plays, and lastly, the three towers of the city cast faint and twisted shadows over the shattered realm. Few who lived to see the fall of this place still live, desperately struggling to deal with their new strange overlord.
All travelers and survivors have come from other worlds, the most populous of which is Earth. Even so, they're all human like in appearance.
Technology is that of modern time, and most can be assumed on a person unless it wouldn't make sense. (A car in Carcosa)
Sanity is slowly lost while in this world, as mere exposure to the horrors within can cause people to start cracking up. Just because you are still sane, doesn't mean you aren't one horror away from seeing something that the mind cannot fathom, usually driving one to temporary (if not permanent) madness. What has been seen cannot be described directly, simply beyond mortal comprehension.
If you're a member of the spires or of the La Troupe Jaun, you serve He Who is King and are -not- sane. Have fun with it and play it up, but remember it is supposed to be Lovecraftian in nature, so try not to go too silly and detract from the setting.