Online:Waters Run Foul

Quick Walkthrough
# Solve the Nedic Puzzle Wheel.
# Defeat the three thralled researchers.
# Find, free and speak with Nahlia.
# Talk to Ralai.

Detailed Walkthrough
In the City Wing of Shada's Tear, you will find Ralai sitting with her back to an altar. She tells you that her cohort, Nahlia, has been kidnapped by their own allies. Several people accompanying them on their expedition into the City District drank the water in the ruins, and they started raving about something called "Shada". When Nahlia and Ralai refused to drink the water, their inebriated friends injured Ralai and dragged Nahlia further into the ruins to be sacrificed. Ralai asks you to find the members of the expedition who drank the cursed water and help her save Nahlia. You'll need to find a way into the next chamber to start your search.

The scroll on the altar, The Light Holds the Way, tells you how to open the door.  
:"Look only to that which shines to show you the true way." —The Light Holds the Way

At the door to the south, there are three Nedic Wheel Locks with different symbols on each side. To solve the puzzle, look at the lit pillars around the main chamber. They have the same symbols on them. The correct order has the face on the left, the serpent in the middle and the dragon on the right. 

In the next room, you can talk to Ralai for more information about how to find Nahlia. You need to find the three missing researchers. Defeat Klause, then talk to his spirit. He expresses remorse for drinking the water and dragging Nahlia off to be sacrificed. Klause tells you that Nahlia is in the final chamber, and that you need to free her before Shada, Master of the Nereids, claims her. 

Continue into the ruin, and defeat Conjurer Squan. He summons daedra, making it a tough fight. Squan's spirit reveals that you need two people to free Nahlia, and that they need to open the locks at the same time.

Continue further into the ruin to Blacksmith Zifri. If she is able to perform Cooled Off without you making it to the safe area in time, you will die. You need to pay attention to the room just before she casts it, when she is standing at her anvil. Her spirit tells you to "look to the pillars for the key."

After all three of the thralled researchers have been defeated, you have all the clues you need to free Nahlia. Go to the room where she is being held. 

You used to have to solve the puzzle at almost the exact same time as your group mate to release Nahlia. Now, you just need to make sure both sides have the correct solution administered, and you can solo it. The solution to the Nedic Puzzle wheels are above the torches on the pillars just behind the wheels. The solution to the northern puzzle is serpent on the left, serpent in the middle, dragon on the right. The solution to the southern puzzle is deer skull on the left, dragon in the middle, deer skull on the right.

Nahlia limps to the corner of the room after you free her. Talk to her. Nahlia says the Nereid Queen, Shada, is responsible for the cursed water in the ruin. A Daughter of Shada is corrupting the waters in this wing. At this point, Ralai shows up. Talk to Ralai. She promises to take Nahlia back to the main camp and thanks you for your assistance.
  

Quest Stages