Use the Desert Map to travel to Keth.
Keth has been buried by centuries of shifting sands. Find a way to access the city proper.
According to Zarka, the Essence of Water can be found in a Sanctum at the heart of Keth. Find it.
According to Zarka, the Essence of Water was kept in a shrine at the center of Keth Sanctum. Find it.
Destroy Azarian, the Forsaken Son to access the shrine that supposedly holds the Essence of Water.
There is a Water Goddess lying in a shrine at the heart of Keth. Talk to her to see if you can render aid.
The Water Goddess has requested you end her suffering. Use the nearby Everburning Cinders to grant her request.
You have used the Everburning Cinders to put the Water Goddess to rest. She will soon be at peace.
Pick up the Essence of Water.
You have burned the Water Goddess alive at her request. Return to the Ardura Caravan.