Steps After Round 10
Building Klaus & Secret Lab Entrance
Once you reach round 10, a Krasny Soldat elite zombie will spawn.
Take him out, and he will drop a battery. It is highly recommended that you DO NOT kill any of the regular zombies from this point onwards, in orer to complete this easter egg on a lower round.
Pick up the battery and make your way to the safe house. Use the robotic hands and the battery to activate Klaus.
As soon as you activate Klaus, run to the Sewer Access just past the Power Room.
You will notice a remote control in your tactical slot. As soon as you get the remote control to command Klaus, command him next to the wall, just past the rope used to rappel up to West Berlin Street.
Wait for Klaus to destroy the wall and reveal the secret lab entrance.
Blacklight & Wonder Weapon
As soon as Klaus destroys the wall, start commanding him around. Keep commanding him to the Switch Control Room, which is located to the right of the Mule Kick perk machine.
The reason we keep commanding Klaus is to prevent him from killing the zombies. Remember, we aim to do this easter egg on a lower round, and we need to optimize our strategy as much as possible. If you leave Klaus idle, he will start killing the zombies.
When you reach the Switch Control Room, command him next to the locker by the wall. Klaus will punch it open, revealing a blacklight inside.
Your flashlight will turn purple. You can switch between your regular flashlight and the blacklight by using whatever your flashlight key bind is. On PC it is 5.
Now, if you're fast enough, you can quickly go and grab the blacklight while commanding Klaus. Or, you can run around the map while commanding Klaus until his battery dies and he returns to the safe house. We recommend commanding Klaus around to avoid any zombie killings.
When Klaus' battery dies off, you will get a message "Klaus Remote Control Device Stowed."
The next step is to find the safe combination using the acquired blacklight. There are three locations where the codes generate. Each location has a number on the wall inside the area representing the order of the numbers on the safe. The numbers shown in the bracket represent the order on the safe. You can find the codes at the following locations:
- Garment Factory (1)
- Sewage Passage (2)
- Grocery Store (3)
There are three spots in each location where the codes can show up, and the spot is random in each game. You can only see the numbers using your blacklight. The following are the locations and the three spots where the numbers can spawn:
The first location is the garment factory. You will notice a '1' on the wall inside the garment factory, which corresponds to the dial labeled '1' on the safe.
The following are the three spots inside the garment factory where a set of numbers can spawn.
On top of the doorway leading to the Korber Rooftop.
On the chalkboard.
A small set of stairs on the wall below the graffiti reads "I Can End This." This is where we got our code which was 34.
The second location is the sewage passage on East Berlin Street, right outside the alley and in front of the bar. This one has a '2' on the wall by the yellow ladder. That means the number in this area corresponds to the second dial on the safe.
The following are the three spots inside the sewage passage where a set of numbers can spawn.
The first spot is on the plain wall under the pipe.
The second spot is above the doorway that leads to the Dead Shot daiquiri room.
The third and final spot is further into the passage. Go through the doorway, and you will find the number on the wall to your right at the end of the corridor on top of the electric box. This is where we got our number which was 32.
The final number can be found inside the Grocery Store. It will have a number '3' on the wall corresponding to the third dial on the safe.
The following are the three spots inside the grocery store where a set of numbers can spawn.
The first spot is by the window to your immediate right as soon as you enter the store.
The second spot is the shelf.
The final spot is in the corner of the grocery store below the poster. We found ours in the corner, which was 18.
In our run, the numbers we got at each location were as follows
- Garment Factory (1): 25
- Sewage Passage (2): 38
- Grocery Store (3): 31
After getting the numbers, make your way back to Hotel Room 305 and enter the combination in the safe inside the barricaded room.
You will be happy to know that the zombies do not attack you while entering the combination. You can hover over the dials by moving your camera when in "enter mode." It can get a bit tricky to know what number the dial is on due to the angle. Our best tip is to count as you move your dial in either direction to avoid this confusion.
When opened, you will find the base variant of the wonder weapon - CRBR-S.
Now, as we haven't killed the regular zombies so far, getting out of this tiny room can get a bit overwhelming. This is where you can use your Aether Shroud field upgrade to exit the room. Do not go mass killing the zombies.