Fighting in the Tower
The Mountain of Fire#67 (x1)
Quest
2A-B (18)
When Revealed: Shuffle the encounter discard pile into the encounter deck and discard cards from the top until X enemies are discarded, where X is the number of players in the game. Add each enemy discarded by this effect to the staging area.

There could not be much doubt: there was fighting in the tower, the orcs must be at war among themselves, Shagrat and Gorbag had come to blows.
-The Return of the King
Forced: At the beginning of the quest phase, discard cards from the top of the encounter deck until an enemy is discarded. If there is a copy of that enemy in the staging area, discard that copy as well. If there is not, add the discarded enemy to the staging area.

This stage cannot be defeated unless Topmost Chamber is in the victory display. When the Ring-bearer is free of encounters, this first player gains control of it.