Past the door is a portal to the Arrival Chamber where you will find several Iron Blade Arrival Guards guarding the Iron Blade Lieutenant. They are weakest to Acid. If your group is small you can use the wall near the surface portal to hide behind so you don't have to fight them all at once. You can lure the Lieutenant easily...his escort will return to their positions if you pull him from near the drop point.
Hei Shou tells you, "Hail, friend! Are you as concerned about the Apostate Virindi threat to Dereth as I am? If you are, I would ask you to investigate a site in northwestern Osteth that seems to be the source of some very interesting energy emanations."
Hei Shou tells you, "Seek the site at 40.1 N, 50.9 W, investigate it to its deepest levels, and bring me back anything interesting that you find. You will be well rewarded."
The Apostate Master whirls to attack and screeches to its minions, "Destroy the Isparian interlopers! Keep the Arrival Chamber sealed! The Isparians must not reveal our deception!"
A shrieking sound pulses from the core of the falling Virindi. As the cloak become immobile a shrill voice sounds in your mind, "Your triumph is temporary and illusory. The mechanical soldiers have accepted our ruse!"
Iron Blade Lieutenant
The Gear Knight turns to attack and announces, "Isparian allies of traitor Asheron detected. Commencing combat protocol. Die, betrayers, die!"
The Gear Knight shudders to a stop and begins to rattle. In a fading voice, it intones, "Power core critically damaged, fragmenting. Protocol fails. Uploading to backup."
Hei Shou tells you, "Fascinating! So you discovered some kind of hostile metal men in that dungeon? And they've destroyed the Apostate facility I asked you to investigate? Well, that's quite a development. I see you brought back some kind of souvenir from your excursion. I'd love to analyze it to learn more about these clockwork soldiers. May I have it? I will reward you, of course..."
You allow Hei Shou to examine your Aetherium Core Fragment.
Hei Shou tells you, "A most interesting find! From what you tell me, the Apostates were ambushing these clockwork soldiers, Gear Knights as you call them, and harvesting their Aetherium for their own purposes. And to use Simulacra to do it, so the Gear Knights blamed us Isparians for it..."
Hei Shou tells you, "Whatever else they are, these Apostates are very clever."
You hand over all of your Aetherium Core Fragments.
Hei Shou gives you Mana Forge Key.
You've earned 12,000 Luminance.
You've earned 396,314,475 experience.
Hei Shou tells you, "I must send news to the Arcanum and to Lord Asheron, and all the royal council... What a discovery!"