As far as Zombie Easter Eggs go, this is one of the easiest ones since the inception of Zombies. This is easiest completed on Solo. When playing solo, during the final step "Boss Fight", the NPC you protect cannot be killed, instead he just gets stunned. It is important that you turn on power and build pack-a-punch before attempting this Easter Egg.
While doing the Easter egg you will need to use specific portals for some steps. If you can't get a portal to spawn, kill a few zombies and check again. If a portal has spawned in the wrong location you need to enter it and when you leave it wait for it to spawn in the location you need. Main Quest - Part 1 - I See Dead People1)
You first need to Build the Aetherscope. The Aetherscope is a buildable item that has 3 spawns across the map that will only appear when inside of the Dark Aether. They will only spawn in 1 at a time so you must go to each location and find the first part before continuing to the next. When you find an item it will have a gold outline from a considerable distance away, so they are hard to miss. You can find the locations here:
Yard (spawn location) - Under the Nacht Stairs to the left of the equipment workbench
Crash Site - On top of the broken plane
Particle Accelerator (pack a punch room) - Next to the Aether tunnel which is centered between the exists to Dead shot Dacquari and Speed Cola2)
Once you have found all the parts you will need to take it to the buildable work table at the bottom of the particle accelerator right behind pack a punch to construct it and equip it.3)
Enter the Dark Aether in the Medical Bay (Speed Cola room) and pick up the journal from the observation deck that will spawn next to the computer up the stairs in the Speed cola room. You will next need to interact with 3 anomalies that spawn inside the facility, once you interact with each anomaly a ghost will spawn in which you will have to interact with to give the journal. You do not need to wait for each anomaly ghost to finish it's cutscene in order to continue to the next one.
Medical Bay - Behind Speed Cola
Control Room (where you activate trials) - On the right behind a reward station
Particle Accelerator - In front of the Aetherscope buildable bench4)
Leave the Dark Aether and Interact with the computer in the Medical bay and it will input a password that will enable the large tube in the centre of the Medical Bay for use.D.I.E. Machine & Upgrades
Before we can do the next step, you need to have the 4 upgrades unlocked for the D.I.E Shockwave (Wonder Weapon). Each time you you are upgrading a new element you must use the base wonder weapon, so equip the standard ammo from the previous ammo box you interacted with before each step.Free D.I.E. Shockwave
1) Kill a Megaton and pick up the golden keycard it drops.
2)Take the keycard to the weapons lab (deadshot dacquiri room) and insert it into the computer opposite the mystery box and pick up the golden D.I.E. Remote Control artefact that comes out of the machine.
3)Go up to the Nacht Der Untoten area of the map to the "Living Room" section and look through the blue gap in the wall and interact with it. This will turn the area in front of the door into suction-like soul box. Let the D.I.E. Machine get 30 kills in front of the door and then interact with D.I.E. Machine through the gap to blow open the door. If you don't get the kills in 1 go that is fine, it will need to cool down so come back in about 30 seconds and try again.
4)Pick up the D.I.E. Machine.D.I.E. Thermophasic
1)First obtain the D.I.E. Machine.
2)Enter the Dark Aether and shoot this fuse box at the Crash Site underneath the floating plane - and pick up the fuse.
3)You will need to have done at least Part 1 of the Main Quest and input the password into the computer before you can continue this upgrade process.
4)Enter the Dark Aether from the Pond area and make your way over to the Weapons Lab area of the facility, opposite Deadshot Daquiri will be a "Plasma Cutter" that you will need to interact with.
5)Make your way back to the pond area and interact with the box on the back of the truck to obtain the D.I.E. Thermophasic.D.I.E. Nova 5
1)First obtain the D.I.E. Machine.
2)Make your way over to Nacht 2nd floor, "Mezzanine," and make your way over to the area where it slides up to the roof. If you look directly ahead you will see a golden cannister, use the D.I.E. machine alternate suction mechanic to bring the cannister to you and then you can pick it up.
3)Make your way to the Weapons Lab and down the stairs where Deadshot Daquiri is and insert the cannister into the West walls "Clearing Unit" and then kill a Plaguehound in front of the machine.
4)Pick up the Infected Cannister from the clearing unit and take it to the small box at the Crash Site against the wall near Stamin-up. Interact with the box and then melee/shoot the cannister. Interact with the box again to obtain the D.I.E. Nova 5.D.I.E. Electrobolt
1)First obtain the D.I.E. Machine.
2)You will need to have done at least Part 1 of the Main Quest and input the password into the computer before you can continue this upgrade process. Please see here for how to do that.
3)You must enter the Dark Aether using only the portal from underneath the Pack-A-Punch, hidden behind the stairs. Whilst in the Dark Aether you will need to find 3 energy crystals around the map and absorb them using the D.I.E. machines alternate charging mechanic. You will only be able to carry the energy of 1 crystal at a time. See locations listed below:
Crash Site - On the right going towards the tunnel
Nacht, Bedroom - On the roof above Stamin-up
Pond - near the mystery box, on the right going towards the tunnel
4)Once absorbed you will need to fire your charged D.I.E. Machine at a small wooden box on the bottom floor of the particle accelerator in the south/south-west corner(
Once all 3 electric-charged D.I.E. shots have been fired at the box you will be able to pick up the D.I.E. Electrobolt.D.I.E. Ice
1)First obtain the D.I.E. Machine.
2)Shoot the box off the top of the ledge from the roof of Nacht facing towards the pond.
3)Make your way down to the pond area and pick up the flask.
4)Have a Megaton spit it's radioactive goop at the fungus on the tree next to where you picked up the flask.
5)Put the flask underneath the fungus and wait about a minute or so and then pick up the flask.
6)Take the flask to the Medical Bay area and interact with the box with the chains on it to melt the chains off. This box can be found next to the door between Medical Bay and the Particle Accelerator. Once complete you can pick up the D.I.E. Cryo-Emiter.Main Quest - Part 2 - Why Won't You D.I.E.You will need to obtain the D.I.E. and have unlocked all 4 variations of it to progress through this step. Please see here for a guide on how to upgrade the D.I.E.1)
Shoot all 4 corners of the container tube with the corresponding D.I.E. machine variation.
Red - D.I.E. Thermoplasic
Orange - D.I.E. Electrobolt
Blue - D.I.E. Cryo-emitter
Yellow - D.I.E. Nova 52)
Enter the Dark Aether Portal that spawns in the doorway between the Medical bay and the Particle Accelerator. You will be able to find another anomaly upstairs in the medical bay outside the Observation Deck that you need to interact with. This will start a short cutscene where zombies will stop attacking you and once the cutscene is finished you will be taken out of the Dark Aether and a Dark Aether Wrench will spawn on the ground where the two spirits were having a conversation.3)
Make your way over to the Yard/Spawn and interact with the tank 3 times to wake up the zombie that is inside it and then kill it. Throw an explosive into the manhole of the tank and it will shoot a bullet at a nearby tree near Stamin-up.4)
Make your way over to the Crash Site area near Stamin-up and you will be able to find a Decontamination Unit on the floor in front of the tree, you will need to pick this up and take it all the way over to the medical bay and insert it into the machine where you picked up the Dark Aether Wrench. (Note: Once you pick the Decontamination Unit up a lot of Plaguehounds will spawn in)5)
You will need to wait for a Megaton to spawn and cause it to split. Once you have split the Megaton you will need to get both halves to go underneath the Containment Tube. They will be sucked inside the tube and you will need to go up the stairs in the Medical Bay and interact with the computer to trigger the in-game cutscene. (Note: All players in the game must be in the observation room to activate the computer)6)
After the cutscene is over you will be in a small lock-down situation where a lot of Megatons and Plaguehounds will spawn in, simply kill these to continue to the next step.Main Quest - Part 3 - Orlov's Revenge (Boss fight)
You will now be entering the boss fight so be prepared before you start the next step. Have strong weapons, killstreaks, armour. Anything that will help with the onslaught.1)
Enter the Dark Aether from the portal in Nacht Der Untoten's "Living Room," and make your way over to the Omega Control Room (the back of Nacht), you will find an anomaly that will spawn in Orlov's spirit and a mini cutscene. Once this cutscene is over and you return from the Dark Aether there will be a "Photograph of Orlov's Family" where the ghost spawned. Pick this up and you will be immediately teleported into the Particle Accelerator room for the boss fight. (if you do not pick this up and start a new round it will despawn and you can't finish the Easter egg, so make sure by now that you are ready, there is no turning back)2)
You will need to protect Orlov whilst he disables the particle accelerator at 3 locations around the room. During this "boss fight" Plaguehounds, Mayaks, Megaton Splitters and Bombers, and normal zombies will spawn in. Some will chase you directly and others will go directly after Orlov. All you have to do is make sure Orlov doesn't die during this step to get to the next phase. (As I mentioned earlier, this is so much easier on solo because Orlov cannot die, he just gets stunned and stops his progress bar)3)
Once Orlov has begun destroying the machine and after a voice queue telling you to leave you will have 90 seconds to get to the Exfil at the pond but beams of light will spawn around the map that will instantly down you. Make your way through either the Medical Bay or the Weapons Bay using jump/mantles to avoid the beams, up through the tunnel, through the Crash Site and into the Pond area to the Exfil site and interact with the helicopter. Once you have done this you will have completed the main quest.