Bold Adventurers the Fountain of Youth awaits your lips….
One day a you are walking on a road to get to a popular city of some sort. All of a sudden you encounter a group of bandits walking towards you looking to start a fight.
The Elven city of Pulca is under siege by a small chaos clan of beastmen. The General of the beastman is a shaman that is attempting to open a warp gate from the the Choas realm. If by any chance the gate is opened many many choatic deamons and abominations will be turned loose on the grand Elvish City of Pulca.
A plague has hit the local area.
In humans it affects only the most vulnerable, the children and the very old, and even than it's little more than a summer cold. 24 hours of sniffles and then it's gone, barely noticeable really.
To sheep however it is fatal and the whole economy of the area is in serious trouble. If this keeps up the area could well be facing famine.
Somebody (enter the PCs) must find the rare herbs needed to make a cure.