Chasing Echoes in WOW is a long questline that has the player take on many tasks in the form of small quests. There are four such quests, and we have detailed all the objectives and the rewards you will get from completing the quests.
Chasing Echoes Full Questline Guide

Head west of Naakroa to find the NPC Om’dalan to start the quest. Get to the spot in the picture above to find the NPC location. First, you need to accept and complete quests: Those We Have Lost and Extended Reach. After completing both of them, you will receive two new quests: Machinations of Memory and Those We Have Yet to Save. Completing all four of the quests will close the Chasing Echoes quest line in WoW, The War Within.
Those We Have Lost Quest
Objective: Collect six Flickering Essence
Once you accept the quest from Om’dalan, you will see a blue-colored region southwest of Naakroa. Get to the region, and you will see many wandering ghosts called Hollow Reflections. Defeating them will yield Flickering Essence and Flickering Primeval Element. Defeat enough of them to get six Flickering Essence, which is the exact amount we need to complete the quest.
After you have acquired six Flickering Essence, head back to Om’dalan to complete the Those We Have Lost Quest.
Reward: Valorstones
Extended Reach Quest

Objective: Gather readings from the Broker Pylons
Here we have to document 3 Nether readings to complete the quest.
Once you accept the quest, you will see an objective marker leading to the first Nether reading pylon, right of Om’dalan. These are basically small pylons with artifacts attached to them; you just have to click on them to start the document process. Once the bar under the screen reaches full, you have successfully documented the Nether.
While the first pylon is located in the safe space, the latter 2 are placed in enemy areas. Take out the enemies and then interact with the pylons to start the document process. Repeat the process three times to get all three pylons documented. Now head back to Om’dalan to complete the quest
Reward: Valorstones
Machinations of Memory Quest
Objective: Interact with four console batteries
After accepting the quest from Om’dalan, he will move into the circular area behind him. Once you are in the room, you will find a console in the middle and four barely visible jar-like figures around it. These figures are the locations for the batteries; you must interact with all four of them to place the batteries in those spots. Once one of them gets placed, the battery will send a charge to the console in the middle. Place all four batteries and turn the quest into Om’dalan to complete it.
Reward: Valorstones
Those We Have Yet to Save Quest

Objective: Recharge six Flickering Ephemera
After completing the previous quest, talk to Om’dalan for the last time to trigger the Those We Have Yet to Save quest. Head down the stairs from Om’dalan, and you will find Flickering Ephemera hovering around the area. Here, use the Nether Tuner quest item on the Flickering Ephemera to test them. You will find the Nether Tuner quest item on the right side of the screen. Repeat the process six times and talk to Om’dalan to complete the Those We Have Yet to Save Quest.
Reward: Valorstones/ Amulet of Final Charge/ Echo Pendent of K’aresh/ The K’aresh Trust Commendation
And that completes the Chasing Echoes questline in World of Warcraft.