Essence of Aether is the third Tier 3 story mission in Act Two of MW3 Zombies, which tasks you to find an Essence Sample from three different locations. These are important for progressing in the storyline and a great way to do gear upgrades.
The samples will be inside some containers at different map locations. The good news is that these samples always spawn at a specific position, unlike many other substances and equipment. So, you won’t have to wander in Mercenary Strongholds and other high-threat areas for your mission unnecessarily.
Sample# 01- Hamza Bazaar
The first Essence Sample is located in Hamza Bazaar, on the far-east side of the Urzikstan map. First, approach the bridge that connects Hadiqa Farms and Shahin Manor. From there, turn to the northwest and walk inside the central building with a Deadbolt Turret on top.
Looking for a Turret icon on your map can help if you are stuck finding the said building. Once inside, you can spot the Sample Container on a table beside the cash register.
Sample# 02- Rostova Shops
For the second Essence of Aether Sample, you must go to the Rostova Shops at Levin Resort, in the northwest portion of the map.
Head into the large building here, and you will find the sample placed on a table on the first floor.
Sample# 03- Quadri Shopping Center
The third Essence Sample in MW3 Zombies happens to be in Quadri Shopping Center. This location is in Zaravan City, in the southwest corner of the map.
Once there, head inside the small restaurant building to find your final Essence Sample container.
Like that, you can obtain all three Essence Samples in Call of Duty: Modern Warfare 3 Zombies.