Here is an example 5 Room Dungeon to inspire your contest entries. In your campaign, you’ll need to flesh out some of the details, but this skeleton format is perfect for GMs to pick up and customize for their own memorable sessions.
The Dragon Isles consist of no less than thirty or so separate islands, of varying sizes, in a fifty-mile chain running on an approximately north-south line about thirty miles off of the eastern coast.
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.