How to complete Mauer der Toten Main Quest Easter Egg in Cold War Zombies

Andrew Highton
cold war mauer der toten disciple

Season 5’s Mauer der Toten map has a tricky and convoluted Easter Egg to complete in Cold War, and our guide will take you through step-by-step to complete this exciting Zombies quest.

As well as trying to survive as many rounds as possible in Mauer der Toten, there are extra objectives and activities for players to be getting on with.

Some searching needs to be done to rebuild the German robot Klaus, players need to find numbers and other items to get the powerful CRBR-S Wonder Weapon, and of course, there’s the main Easter Egg quest to complete.

We’ve put together a full guide on what to do and where you’ll need to go to do the Mauer der Toten Easter Egg in Black Ops Cold War Zombies.

Mauer der Toten Easter Egg guide

mule kick perk machine in cold war zombies

Strap yourself in as there are typically going to be many steps that comprise this tough and testing quest in Mauer der Toten.

Follow each step carefully, and you should have no problem doing this yourself.

1. Build Klaus

klaus robot in mauer der toten

As we mentioned earlier, one of the fun side activities that players can do as they play Cold War’s Mauer der Toten is build Klaus. He is a sassy robot that will assist the players in the lobby by shooting enemies and reviving any downed players.

But before any of this, you’ll need to scour the map and complete certain steps to assemble him. Check out our in-depth guide on how to build Klaus in Mauer der Toten to complete this first step.

2. Obtain the CRBR-S Wonder Weapon

crbr-s wonder weapon

Now that you have Klaus raring and ready to go, it’s time to use him to obtain the combination to the safe in the room you found his hands.

Once again, this asks you to complete a few different fiddly tasks to get the insanely powerful Wonder Weapon, and we’ve simplified the process with our how to get the CRBR-S Wonder Weapon guide here.

3. The Sewers Wall

secret lab wall in mauer der toten

With Klaus built and the CRBR-S in your hands, we can now press forward to the next crucial stages of the quest.

You’ll need to head underground and access the “Sewer Access” room. In here, select the wall in the picture, and in the same way, you’ve had Klaus smash open the locker to retrieve the black light, Klaus will actually obliterate the wall.

Behind this wall is another reinforced wall, and to get past that one, you’ll need to keep killing Zombies until one drops the “Blazer Mod kit” for the CRBR-S.

Equip the mod, and then proceed to unleash hell on that wall until it melts a hole through it, then enter through it.

4. The Secret Lab

cod zombie secret lab cold war

You’re now inside the lab that the main action will take place in, and the first course of action is to keep playing until the red shields protecting two pieces of equipment go away.

Next, pick up the three canisters in the middle platform that were protected by the shield, and kill some Zombies with the CRBR-S. Make your way over to the other device that was being shielded, and then claim the ‘Endstation Lure.’

5. Search Mauer der Toten for the Essence Harvesters

essence canister in mauer der toten

It’s now time to venture back out into the map and start finding Essence Harvesters, and there are three in total.

Once you arrive at once, activate it by placing an empty canister in the machine, and throw the Essence Trap on the ground. This will spawn Tempests, kill them, and then collect the now full Essence Canister.

The tricky part comes next as you’ll have to carry the canister all the way back to the Secret Lab and not allow it to become damaged. Once there, place it in the platform that you took the canister from originally, grab another trap, and then rinse and repeat with the remaining two Harvesters.

6. Upgrade Klaus

klaus in his upgrade station

We’re leaving the Secret Lab again, and it’s now time to upgrade Klaus. To do that, you need to keep spawning Klaus in after he’s recharged. Either approach him in his chair or find radios scattered around the map.

The goal is to let Klaus rack up enough kills so that the screens on the ‘Garment Factory’ stand turn green. Once it does this, command Klaus to get into the unit, and you will then have to defend him for a full minute.

Upon successful completion, you now need to head into the underground and go to the train tracks. He will comment that he will stop one of the trains, and then you need to go inside to the ‘Switch Control Room’ nearby and trigger the Railway Switch.

7. The Train

klaus stopping the mauer der toten train

Head back to the platform to observe Klaus as he miraculously brings one of the trains to a halt. Now is your chance to board the train, grab the ‘Bomb” and ‘Rico’s Keycard.’ With both of these items claimed, it’s time for another trip to the Secret Lab.

As soon as you’re inside, place the newly-acquired bomb into the cradle holding the three filled canisters. From there, it’s another journey, this time to the room you can find Klaus recharging in his chair.

In this room is a computer with the words “Keycard Required” displayed on the monitor. Insert said Keycard and select ‘Browse The Files.’

The objective is still not complete as you now want to make Klaus’ headgear.

8. Klaus’ headgear

Klaus with headgear in Mauer der toten

From the computer, you’ll now have to trek all the way to the beginning of the game on the rooftop where you originally spawned. If you look up, you will see a mini-pylon that you need to shoot the top off with the CRBR-S.

An item will then fall off of it, and it will be an ‘Antenna’ for you to pick up. Next, arrive at the ‘Electronics Store’ and shoot all the radios inside the shop – collecting the ‘Transistor’ in the process.

Finally, head back down to the ‘Ghost Station,’ and you’ll see a power box above the ticket booth to allow yourself to claim the ‘Electronic Boards.’

With everything in your possession, return to Klaus’ chair and press to ‘Craft Hacking Helm.’ Access the computer once more, and this time Klaus will give us access to the satellite.

9. Activate the Satellites

satellites in mauer der toten

Our first one is in the room with Klaus, just press to ‘Activate the Disruptor Satellite’ on the computer that required the Keycard, and that will be the first one done.

Onto the next one, and we can find it in “West Berlin Street” in a green tent next to the Trial Station. The final one can be located in ‘East Berlin Streets’ and is similarly tucked away in a green tent.

10. The Boss Rush + Radioactive Materials

piece of uranium rock in mauer der toten

Just when you think things couldn’t get any more strenuous, head to ‘Checkpoint Charlie’, and you’ll now have to endure a wave of tough Megatons, Manglers, Mimics, and Krasny Soldats.

When the final Megaton is killed, go and pick up the ‘Uranium Rock.’ This will initiate a five-minute countdown timer, so take the rock to the workbench in the tent you found the second Satellite in’West Berlin Street’.

Craft the Uranium device and swiftly head to the beginning of the map to attach the device to one end of the zipline that travels between two buildings.

G back to ‘Checkpoint Charlie’, grab the other Radioactive rock, repeat the whole process, and this time attach the device to the other end of the zipline. If it’s worked, the materials will fly down the zipline until they collide with each other, explode, and drop ‘Cleansed Rock.’

Take it to the Secret Lab and deposit it on the platform with the three canisters. Sadly, the whole process now needs to be repeated to create one more piece of Cleansed Rock. Meaning killing another Megaton, claiming the materials, and repeating all the previous steps, e.g., taking the rock to the table, making the device, and strapping them to the zipline.

Collect the second rock produced by the zipline explosion, and we can finally head towards the endgame.

11. Secret Lab & Doctor Valentina Boss Fight

doctor valentina boss fight

It’s finally time to finish this once and for all. Doctor Valentina will spawn through a Portal in the Secret Lab, and you now have to kill her!

The main takeaway here is that you need to stay consistent and damage her. If left unharmed for a few seconds, she will regain her shield.

One crucial thing to note here is that you can go around the map, buy armor, ammo, build Scorestreaks, etc., to help you with this fight.

She has different phases and attacks, with the main one to watch being a move that can absorb health from other Zombies – stop her from doing this.

Her other devastating threat is a charged-up attack that can one-shot you, even if you have full armor. Take your time, be strategic, and you should be able to beat her.

After the cut-scene, there is a task, and that is to protect Klaus as he slowly walks towards the portal. Do this, and you will have completed the Mauer der Toten Easter Egg!


If you enjoyed this guide, why not check out how to complete the Die Maschine Easter Egg, the Firebase Z Easter Egg, or the Outbreak Easter Egg.

Also, make sure you’re on top of all the latest Call of Duty: Vanguard details, especially its Treyarch-developed Zombies content.

Image Credit: Activision / Treyarch