Stay a few nights in one place and a horde may appear at the edge of the land. It's drawn as a knot of the risen with a countdown ("horde: 1 night"), and it moves one field closer each night.
On the night it reaches the camp, it's added to that night's attack, and the forecast warns you that morning. Leave before it arrives and you escape it; a new camp can see its own horde later.
This gives the question the Pilot is testing a sharper edge: moving is now a decision you make ahead of time, not something that happens after the walls fall. Version v0.0.6.