Deeper into the Past
The Ruins of Belegost#3 (x1)
2C-D (9)
When Revealed: Shuffle Lurker of the Depths and the encounter discard pile into the encounter deck. Discard cards from the top of the encounter deck until a location is discarded. Add the discarded location to the staging area.

The keys you discovered unlock a passage that leads deeper into the mines of Belegost. As you descend further into the Dwarven city, you marvel at the enormity of its size and the complexity of its design.
The player cannot advance unless they control at least 2 Loot objectives and there are at least 3 resources here.

Forced: After the active location is explored, place 1 resource here.

Forced: When this stage is defeated, if Book of Aulë's Children is attached to a hero, advance to stage 3E. Otherwise, advance to stage 3C.

You must carefully explore the ruins to ensure you don't miss anything.