Global quests: Invasion

Invasion is a global quest in which heroes must rid the world of one threat or another -- for example, ravenous locusts, multicoloured bubbles, or a sudden ice-over.

For example, locusts spread across all places where they can feed on vegetation (looking for them under the mayor's bed is probably not worth it). Locusts, bubbles and the rest of the plague are visible via the where command -- the main thing is not to be lazy, keep running around and searching.