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.
The villages around the capital have a strange new disease cropping up. Spread by a fungus (much like ergot poisoning), it causes its victims to be very sensitive to sunlight. Hundreds of peasants are hiding from the sun, only coming out in the darkness to labor in the fields. Unfortunately, rumor makes their behavior sound more sinister and secretive than it really is.