Firebase Z is the second map released for Black Ops Cold War Zombies. Firebase Z brings back several classic gameplay mechanics and features such as "soul charging" and round skipping to progress the main easter egg. This means that as more time passes since the map was released, players will certainly find additional "round manipulation" techniques to complete some steps during the early rounds, which might not be possible otherwise. We've adopted a similar strategy in our guide to obtain the power cell for the RAI K-84 in the early rounds.
Before proceeding with the main easter egg, ensure that you have turned on the main power by activating the three main Aether Reactors around the map. It is relatively easy as you can do it by following the on-screen indicators to reach each reactor. You also need to build the pack-a-punch machine, which is done by returning to Ravenov after turning on power by activating all three reactors. You may check out our guide on how to turn on the power and build the pack-a-punch machine here.
The Dark Aether story continues in Firebase Z where you unveil the story further by performing a brand new easter egg that leads up to the rescue of Samantha Maxis, who is no stranger to the zombies community. In this easter egg, you (the Requiem team) are tasked to find Samantha and rescue her from the Dark Aether. You and the team visit the Firebase to find her only to discover she has been sent to the Dark Aether.
You are then tasked to retrieve her from the Dark Aether by opening a portal that takes you to it. You have a new ally named Ravenov who is a Spetsnaz but against the Omega (enemy) group. You also have Dr. Peck who was leading the zombies research at Firebase for the Omega group. You will need to carry out certain steps to create a truth serum that is used on Dr. Peck, so that he may spill the truth about reopening the portal.
According to Dr. Peck, you need the memories of three fellow colleagues to open the portal and locate Samantha in the Dark Aether. The names of the three scientists are Brahms, Sokolov, and Zhabin. These scientists have turned into Mimics (a new elite zombie in Firebase Z) who can disguise as different salvage drops on the ground. You have to use an essence trap to trap these Mimics and bring them back to the Data Center to reveal the information via Memory Transference Station.
After collecting all the information, the mainframe is activated and the portal is opened, only to then destabilize. After talking to Dr. Peck he reveals that there are three Aetherium crystals around the map that can power up the portal. You find them, one of which requires the wonder weapon RAI K-84, and insert them into the three Aether Reactors to reopen the portal. Once the portal opens, it shuts off once again thanks to Dr. Peck's cunning plans.
Finally, the Satellite dish at the base is used as the medium to power the facility and reopen the portal after which Samantha comes out of the portal. As Samantha is leaving with the Requiem team, they are faced by the giant Orda who is the final boss on the map Firebase Z. Defeating Orda will finish the main easter egg of Firebase Z.
The Truth Serum
Assuming you've already turned on the power and built the pack-a-punch machine, we will proceed to the easter egg's truth serum step. After turning on the power, wait for Peck to call you to speak to him at Mission Control. This is where one of the Aether Reactors is located to the far left of the map next to Scorched Defense.
Go to Peck, and interact with him to speak to him. Wait for Peck to finish talking, and you will notice that he doesn't hold his end of the bargain to return Samantha Maxis upon turning on the power, hence the reason we need the truth serum.
After he's done talking to you, Ravenov will ask you to meet him. Head back to the spawn and talk to Ravenov again. Once he is done talking, he will give you his ID card that can be used to open up various lockers containing the compounds for the truth serum that are located around the map.
Take the ID, and make your way across the street from Ravenov and enter the building with the purple arrow. This building is called Equipment Storage. You will find your first locker here. You will see a keycard access point on these lockers, so they are not hard to identify.
Interact with the locker to swipe the card, open the locker door, and reveal the first compound called 'Compound S16.'
The second locker is located in the Engineering building next to the OPC dome when you go through the left gate from the helipad area once you go through the portal. This compound is called 'Compound 36.'
The third and final locker is located in Colonel's Office in the Military Command Control Room building. This compound is called 'Compound P65.'
After getting all three compounds, make your way to the Field Hospital past the Barracks (reached via a middle gate from the central helipad area).
You will find a chemical mixer on one of the tables inside. Use it to mix the compounds.
As the mixing comes to an end, several hellhounds will spawn, so be careful when dealing with them as they do quite a lot of damage.
After taking care of the hellhounds, interact with the mixer to transfer the mixture to the Gas Dispersal Device.
After transferring, you will be able to pick up the whole device.
Pick it up and take it to the OPC platform. You will find an Air Conditioning unit that will be directly above Peck's room. Place it on top of the air conditioning unit.
After putting the device on the air conditioning unit, return to Peck, and he will have a long conversation with you (including some dancing). He will mention the names of some scientists. The names are Zhabin, Brahms, and Sokolov. You need to find them as they have been turned into Mimics. More on that in the Mimic step below.
Once he is done talking, he will ask you to go to the Data Center. Make your way to the Data Center and interact with the Memory Transference Station to unlock it.
Once unlocked, you will be able to pick up the Essence Trap that can be used to trap the zombies to download their memories. There is also a side easter egg associated with the essence trap called the Safe Easter Egg.
Now, as far as the main easter egg goes, the essence trap is used to collect three scientists' memories (Zhabin, Brahms, & Sokolov), but we will do that after collecting some RAI K-84 wonder weapon parts. We do this first, in order to get the power cell early, or else it doesn't spawn until after Round 15. The Mimic step will be done after the RAI K-84 wonder weapon parts collection.
RAI K-84 Wonder Weapon
Make your way to the Weapon Lab and collect the RAI K-84 blueprint off the wall.
Then make your way to the Scorched Defense area next to Mission Control, and get Dimitri's eyeball by gauging it out. Dimitri's body will be resting next to the crashed tank to the rightmost section of the Scorched Defense area.
Interact with the body, and a mini cutscene will play where your operator will gauge the eye out. Don't worry - the zombies won't attack you during the cutscene.
Return to the Weapon Lab, but before proceeding, keep one zombie alive at the end of the round and trap him using the essence trap to make the next steps more manageable for you. When the essence trap turns purple that means that you've successfully captured the zombie. The zombies stay in the trap for 3 minutes before escaping and destroying the essence trap in the process.
Now, use Dimitri's eye on the Retina Scanner to unlock the computer, and the computer desk drawer will open up, revealing a locker key.
Pick up the key and make your way to the Barracks area once again. You will see two green buildings labeled '1' and '2.'
You will find locked lockers inside the Barracks. Keep opening up the lockers until you hear a Mimic spawn.
Once a Mimic spawns, kill him, and he should drop the Barrel Assembly for the RAI K-84. Sometimes you need to open multiple lockers to get the right Mimic. Multiple Mimics can spawn.