It can be dangerous trying to send someone a message. Spoken words may be overheard, written correspondence may be intercepted, and body language may be seen. Did you ever wish you could think the words and they would be known?
Gareth turned and squinted uneasily over his shoulder. He could have sworn he heard a high pitched hiss. He turned back to continue through the dim underground passageway. It was then that he saw them. A pair of ruby red eyes, glowing faintly a few feet front of him. He had to look up to see them, and that is saying something, given Gareth’s generous stature. The strike was quick…he had no chance. The last thing he remembered were the eyes hovering above him and the fangs dripping venom. And was that a second set of eyes gleaming beneath the first…?
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.