Encounter set:
Foundations of Stone
Encounter info:
Foundations of Stone, Twists and Turns, Goblins of the Deep, Deeps of Moria
When Revealed: Create your own staging area. Discard all resources from your heroes.
Forced:
After the 17th progress token is placed on The Endless Caves, join another player at the beginning of the travel phase. If you cannot join another player, all players continue on to stage 5 together.