A dangerous, alien plane where glowing frog-slimes slither and slurp, metal-skinned bird people rebuff diplomacy, and only the endless subterranean tunnels are safe (just mind the gravity-bending moles). Visitors will have to skulk around in the dark to avoid the curse carried by the sunlight. Because (have I mentioned?) the sun is the source of a powerful curse--one that covers the whole planet.
A supposedly empty desert on the far side of the mountains has started growing. No one knows why. At the center of the desert lies a tall rock outcropping, hundreds of feet tall. Dust storms shroud the outcropping constantly, except for one night a year.