Stones that have been attuned to the extreme temperatures of deserts or icy wastes. Such stones are quite valuable to adventurers as they can use them in order to preserve or prepare meals, make extreme environments bearable, and use them in clever devices.
A land is reigned by a circle of powerful men who control every aspect of the citizen's life. This cabal changes members often. In reality, the spectres of a small necromantic covent possess and control the people in power. Since they simply possess the bodies, they can leave when old age overcomes their shells and possess a new up-and-coming noble.