“ Temple of some malign being invites you warmly and offers help (curing,needed spell etc) for some minor sacrifice . Sacrifices must be everytime bigger to work - up to living inteligent creatures. Maybe you pay some other price,too...”
“ A terrible affliction spreads through the land: A disease, highly contagious, which makes its victims mildly ill, but then permanently paralyzes the vocal cords. Dozens of reputed cures and protections are sold in the marketplaces, which gradually grow quieter and quieter...”
“ A cave with weapons sunken into the walls, blades sticking out of the floor and ceiling, and so on. Possibly, any weapon used in it could be torn out of the hand and sink into the stone.”