There are ruins, scattered about the world, and all are sealed with unbreakable locks.
When all of these locks suddenly open, what emerges?
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.
There are two major (read feuding) provinces in the kingdom. The Lord of one is secretly a mad, power-hungry despot, constantly plotting against the king. The Lady of the other is secretly an ancient silver dragon.