“ <br />
Real world scientists have accidentally opened a tear in the fabric of reality, transporting their laboratory into the game world. Unable to repair and/or refuel their equipment in this (to their minds) primitive world they are now trapped.”
“ Dust Elemental
https://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=1594
At the corner of air and earth elemental planes resides the dust Elemental, a growing threat to Parisia. With it's powerful choking attack, this creature is a threat to the city. More and more of them are appearing in town, spawned from the many dust devils, a frequent foe of the party, they come in size from 3 HD to 20 HD. Why are there so many? Why in the city?”
“ <br />
A plague has hit the local area.<br />
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.<br />
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.<br />
Somebody (enter the PCs) must find the rare herbs needed to make a cure.”