A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.
Unbeknownest to the character, he is in the royal bllodline. Suddenly the majority of royals fall ill and die, and the hero is left with the crown, but no experience or idea of what to do.
A Deity of some sort has unleashed a plague of bookworms or something like that in the area. Almost all spellbooks are destroyed, along with bardic and historical books.
The Pcs discover an ancient, dusty oil lamp, somewhere in the bowels of a dungeon. Naturally they "rub it", and out pops a wizened, old djinn. So far so good. Then it speaks...
"Ah at last, at last I am free! Now grant me my wish!"
When the PCs explain that they are the ones that should be granted a wish, the malignant djinn explains to them that his particular oil-lamp has a curse placed upon it. Whomsoever releases the entity inside shall be geased to grant the djinn's wish to the best of their ability.
Groans ensue from the party. The djinn rubs his wrinkled hands, grins, and proceeds to name his wish. What could it be?