We go up the stairs on the left, where there's another suicide bomber with his back to us.
Let him detonate, then continue up the stairs. On the left side of the stairs, you can pick up a Dust item.
After picking it up, head right. There's a save point and a Ghost Slayer on the right. Save your game and talk to him.
The "Isolation Wedge" quest will also update.
We'll head right now. The door at the very front is locked and won't open, so let's take the elevator down.
After coming down, keep heading right, defeat the enemies ahead, and collect the items.
Let's keep going down. We can see a save point ahead, but let's not head there just yet—there's another path leading down on the right.
There are tons of enemies below.
After clearing them all, grab the two chests up ahead.
The one on the left is Blackstone Fragment #2.
