From the drop, head east and then take your first right. Head straight south and down a ramp. Hug the right wall and continue down a series of ramps until you reach a pit. Jump down and make your way south into a large room. This room contain Simulacra - once you have cleared the room find the way out on the west wall.
This dungeon is the most dangerous of the three containing Dual Elementals, Hollow Olthoi, Martinate Simulacra, and Virindi.
Once you arrive in the dungeon, head west to a dead end. Turn to face north and go down a ramp and then go east and down another ramp.
You should end in a large room with a large ring in the middle. Take the north or south exit and head down the ramp. Make your way east killing both Duals and Virindi.
Both corridors lead to a large open room, filled with more Duals, Virindi, and some Hollow Olthoi. Dispatch these and then make your way toward the door in the middle of the east side wall. Make your way through it and you will reach the final room. There is section in the middle of the room containing Martinate Singularity Trove. Use your key and grab the Quiddity Ingot.
Part 3: Obtaining the Quiddity Weapon
The inscription on the Ingot gives you the coordinates 32.0N, 43.2W. Go here to receive your weapon by giving the Ingot to the appropriate Virindi Crafter.