Mauer der Toten’s main quest is completely SOLO-capable, or you can complete it in co-op.

1. ⚡ Restore power

Work your way from the 5th Floor Apartments down through Berlin and into the underground Power Room.

Trying the power switch reveals that you’re missing two fuses.

Two Tempests appear in the underground sections. Defeat both and collect their:

⚡ Electrical Fuse #1
⚡ Electrical Fuse #2

Insert both into the power box and flip the switch.

⚡ POWER ON.

Head back toward Checkpoint Charlie and clear the enemy encounter around Pack-a-Punch to unlock it.

2. 🤖 BUILD KLAUS

Klaus is sitting deactivated in the Safe House.

You need two components.

🔋 Battery

Wait for a Krasny Soldat to spawn and defeat it. Collect the battery it drops.

🤖 Robotic Hands

Go to Hotel Room 305.

Use Brain Rot on a zombie near the boarded doorway so it destroys the barricade.

Enter the hidden room and collect the hands.

Bring both components to Klaus.

🤖 KLAUS ONLINE.

You’ll receive his remote control, allowing you to command him around the map.

And yes, he has opinions about basically everything. 😂

3. 🔫 Obtain the CRBR-S

The CRBR-S is Mauer’s Wonder Weapon.

You can get one through the Mystery Box or Trials, but there’s also a guaranteed quest.

Have Klaus interact with the locker inside the Switch Control Room.

Collect the Blacklight.

Now search three locations for hidden numbers:

Garment Factory

Service Passage

Grocery Store

Shine the Blacklight around each room until you find its two-digit number.

Write them down in order.

Go to the safe inside Hotel Room 305 and enter:

Code #1 → Code #2 → Code #3

Open the safe.

🔫 CRBR-S ACQUIRED.

4. 🤖 Upgrade Klaus

Klaus needs to become considerably stronger before the main quest can continue.

First obtain the Microwave Dish by searching the debris piles around the Death Strip.

Install it into the Garment Factory upgrade station.

Activate Klaus and command him to stand in front of the machine.

Before it’ll accept him, Klaus needs enough zombie eliminations.

Once he’s ready, he’ll tell you.

Put him into the machine.

🚨 DEFEND KLAUS.

Survive while the machine upgrades him.

Once completed:

🤖 KLAUS LEVEL 1 UPGRADE.

But we’re not finished with him yet.

5. 💿 Find the TWO floppy/cosmetic disks

You’ll find electrical boxes around Berlin marked with a small Klaus symbol.

An upgraded Klaus can punch them open.

Two of these boxes contain Cosmetic Disks.

Collect both.

Take them back to the Klaus upgrade machine and use them to finish his upgrades.

We now have:

💪 SUPER KLAUS.

Which is good, because we’re eventually asking him to stop a train with his bare hands.

6. ⛑️ Build Klaus’s Hacking Helm

You need three components, all obtained using the CRBR-S:

📡 Antenna: Shoot the antenna on the Apartment Rooftop.

📻 Transistor: Shoot the radios inside the Electronics Store until the component pops out.

🔌 Electronic Boards: Shoot the electrical box in Ghost Station opposite Mule Kick.

Collect all three.

Return to Klaus and install:

⛑️ HACKING HELM.

Now Klaus can access systems we can’t.

7. 🧱 Open Valentina’s Secret Lab

Head into Sewer Access.

Command Klaus to stand near the suspicious brick wall.

👊 KLAUS SMASH.

He punches through it.

Behind the bricks is a reinforced metal wall.

You need the:

🔥 CRBR-S BLAZER MOD

Use its beam on the metal doorway until it melts.

Welcome to:

🧪 VALENTINA’S SECRET LAB.

8. 🧪 Charge THREE canisters

Inside the laboratory are three empty canisters.

Collect them.

Place each one into an Essence Harvester around Berlin.

Then use the special lure interaction to summon Tempests.

Defeat the Tempests close to the Harvester.

Their energy fills the canister.

Repeat until you’ve charged:

🧪 Canister #1

🧪 Canister #2

🧪 Canister #3

Return all three to the Secret Lab.

9. 🚆 STOP THE TRAIN

Head to Ghost Station.

Use the track-switch controls.

Then activate Klaus and position him directly on the train tracks.

And now we ask our robot friend to do something completely reasonable:

🤖✋ STOP A MOVING TRAIN.

The train arrives.

Klaus physically stops it. 😂

Quickly enter the train.

Collect:

🔑 Keycard

☢️ Warhead

Take the warhead back to Valentina’s laboratory and install it into the device.

10. 🛰️ Activate the Disruptor Satellite

Take the Keycard to the computer terminal in the Safe House.

You’ll initially be denied access.

That’s why we built Klaus’s Hacking Helm.

Have Klaus hack the terminal.

Access the satellite controls and activate the Disruptor Satellite.

A giant beam hits Berlin.

Enemies begin spawning.

Among them is a special Megaton.

Defeat it and its split forms.

They drop:

☢️ CORRUPTED URANIUM.

And now:

⏱️ MOVE.

The uranium portion has a roughly five-minute timer, and failing it can end the run.

11. ☢️ Craft TWO Uranium Devices

Pick up the two uranium pieces.

Take each to a crafting bench and turn them into:

☢️ URANIUM DEVICE #1

☢️ URANIUM DEVICE #2

Carry them to the two rooftop zipline locations:

🏢 Destroyed Penthouse

🏢 Korber Rooftop

Attach one device to each end.

They travel down the ziplines toward each other.

💥 CRASH.

The collision produces a:

💎 CLEANSED ROCK.

Pick it up and return it to the Secret Lab.

Place it into the warhead.

12. ☢️ DO IT AGAIN

Unfortunately, one rock isn’t enough. 😂

Advance the round.

Activate the satellite sequence again from the appropriate terminal.

Another HVT Megaton appears.

Defeat it.

Grab both uranium pieces.

Craft:

Device #1

Device #2

Put them onto the two ziplines.

💥 Crash them together.

Collect:

💎 CLEANSED ROCK #2.

🚨🚨 POINT OF NO RETURN 🚨🚨

DO NOT PUT THE SECOND ROCK INTO THE WARHEAD UNTIL YOU’RE READY.

The instant you insert Cleansed Rock #2, the Valentina boss fight begins.

Get your armor, perks and equipment sorted first.

Then return to the laboratory.

Insert the second rock.

👩‍🔬 13. VALENTINA BOSS FIGHT

VALENTINA

appears inside the Secret Lab.

She has:

🛡️ Shield

❤️ Health

Break her shield first.

Then damage her actual health.

She has several dangerous abilities.

🔥 Projectile attack

Use environmental cover and keep moving.

💀 Wipe attack

When the screen gives you the distinctive blue warning effect:

GET BEHIND COVER.

This attack can down players extremely quickly.

🧟 Healing

Valentina summons floating zombies and drains them to restore health.

Kill those zombies before she can consume them.

14. 🏃 Chase Valentina through Berlin

After taking enough damage, Valentina retreats.

Follow her.

The battle progresses through multiple areas of Berlin.

Each time:

Break shield → Damage Valentina → Avoid attacks → Stop healing → She retreats

Then follow her to the next arena.

Eventually she returns to:

🧪 THE SECRET LAB.

15. 💥 FINAL DAMAGE PHASE

This is it.

Break Valentina’s shield again.

Unload everything you’ve got.

Stop her from healing.

Avoid her wipe attack.

Keep damaging her until—

💥 VALENTINA DEFEATED.

But we’re not done.

Because Klaus has one last job.

🤖 16. DEFEND KLAUS

Klaus picks up the completed inversion warhead.

He starts carrying it toward the Dark Aether portal.

Zombies attack from everywhere.

PROTECT KLAUS.

Clear enemies away from him so he can continue moving.

Eventually Klaus reaches the portal.

He carries the warhead inside…

💥

…and doesn’t come back.

🎬 TIN MAN HEART — COMPLETE

The ending cutscene plays, pushing the Dark Aether storyline toward its final confrontation.