You can get the collectible in the alcove from the side where the Ochre Jelly appeared
The quest is pretty straightforward. You just need aion online gold to go to different sections of the sewers to turn valves. You can only proceed to the next section after you have turned the valve found in the previous section.
WALKTHROUGH - Upon entering, you will notice that there's only one way to go and that's to head down south. Just across from where you are standing, you will see a locked metal door. As you head to that direction, you will be able to target a Gray Ooze (CR: 3), but it won't actually show up until you get to the door.
The Grey Ooze will come from the left side, while a Large Ochre Jelly will come attacking from the right side. After killing them, you can get the collectible in the alcove from the side where the Ochre Jelly appeared, or head east since you can't open the door just yet. You will then reach the water area where the path slopes downward.
As you thread the waters, Lesser Gray Oozes (CR: 1) will attack you from behind. At the far end is a Huge Violet Slime (CR: 3) that's protecting the first valve which opens the metal door. Another Lesser Gray Ooze will attack, this time coming from up top.
