One of the captives stumbles for exhaustion, and the noise alerts the guards.
When Revealed: The first player adds Uruk Chieftain to the staging area. Each player chooses a hero he controls, discards all tokens and attachments from it, and attaches it to an unattached enemy in the staging area as a captive. Then, the players make a standard series of engagement checks against each enemy in the staging area. Reduce the engagement cost of each enemy not guarding an objective to 0 during these engagement checks.
Horns echo through the dungeon, and the Orcs come running with weapons drawn. You will have to fight past them to escape.
Forced: At the beginning of the quest phase, discard cards from the encounter deck until an enemy is discarded and add that enemy to the staging area.
The players cannot defeat this stage while a guarded objective is in play. If the players defeat this stage, they win the game.