Forced: After the players travel to Torch-lit Hall, 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 just discarded enemy to the staging area.

It was dimly lit with torches flaring in brackets on the walls, but its distant end was lost in gloom.
–The Return of the King