Shutting down their operation is just half of the plan. The other important goal here is to find out where all that Saronite is being sent. We know of a few places it's been ending up, but the amount they're pulling out suggests to me that there's a bigger project in the works.
Once you're inside the quarry, get your hands on any of their documents that you can find. If you're assaulting the place with one of the gryphons, you can drop down from it as soon as the wetwork is done.
Did you bring back what I requested?
Let's see here... what do we have...
<Keritose buries his head in the papers for a bit, seemingly gleaning little that he did not already know. Suddenly he finds what he is looking for...>
Malykriss! The Vile Hold. It seems Arthas did not take the loss of his death knights so well... I'm not exactly sure what he's doing with all of that Saronite, but I have a feeling he might be overcompensating for something.
That boy is not used to losing.
The four quest items are in separate camps in or near the tents.