Commander Mar'alith at Cenarion Hold in Silithus wants you to find his beloved Natalia. The information that you gathered points to Hive'Regal in the south as being the area in which you may find Mistress Natalia Mar'alith.
Do not forget to visit the dwarves at Bronzebeard's camp before venturing into the hive. They might have some additional work and advice for you.
And <name>, remember the Commander's words: "Do what you must..."
I need you to venture into Hive'Regal and find what became of my dearest Natalia, <name>. This will be no easy task for you. Before you dive headlong into the maw of madness, make sure that you speak with those dwarves further. They might be able to give you some tips on dealing with the silithid that inhabit that hive.
And <name>, if she truly is as mad as they say... do what you must.