'For your final task, Name, you will take this battle-horn into the Hudnul-meden and look for the battle standard of the orcs therein. When you find the standard, make use of it and defeat the Orcs that come to the horn's call...and come they will. There is no way they can ignore the insult of their former leader's battle-horn being used to challenge them.
'Begin your search in a place where many orcs gather. It is likely that their standard is there; and more likely that the orcs will answer the call of their fallen leader's battle-horn.
'Remember that your task in this fight as a captain is to inspire your fellow warriors to continue the fight.
'When you have won the battle, return to me.'
The call of Nanulg's battle-horn would be such an insult to the Orcs of the Hudnul-meden that they would not dare to ignore its call.
Objective 1 Use the summoning horn in Fil Gashan The Hudnul-meden lies in the south-western reaches of the Flaming Deeps.
Garnyd has instructed you to use Nanlug's battle-horn to challenge the Orcs in the Hudnul-meden.
Objective 2 Talk to Garnyd at Anzamekhem Garnyd is at Anzâmekhem, north from the Hudnul-meden.
You should return to Garnyd with news of your victory.
This quest completes the lvl 58 class quest line for Captains. The quest "Hands of Healing" is available to other classes, AND Captains, to help kill the waves of orcs that come in FG when the summoning horn is used. (The reward is a Mark of Victory.) The quest requires a full group. Currently, a Captain can do both In Harm's Way AND Hands of Healing and get credit for both with one run of FG. This is probably not intended by the Devs.
Once the summoning horn is used in Fil Gashan, wave after wave of orcs floods into the cafeteria, and the goal is basically to survive. There is no "boss" per say, your job is to take out all of the orcs that will spawn.