There are two ways of completing this achievement, both of them must be done in the Original difficulty setting. One way is by listening to Dr. Maxis, and can be done only when the power on the map is turned off. The other way is by listening to Richtofen while the power is turned on, however the only character that can hear Richtofen is Samuel and does not work if Samuel is not in the game. This method does not require the NAV table to be built, as it has been completed without it, but the Thrustodyne Aeronautics Model 23, must be built in order to complete it, which Richtofen makes comments of having to be built after the power is turned on.
Once a player has completed one side of the Easter Egg, it will count as having been completed for that side in all subsequent playthroughs. In order to do one side of the Easter Egg a second time, the player will need to have completed the other side first, which will in turn lock that side, or have activated the endgame on Buried, which will unlock the Easter Egg so that either side may be completed. Alternatively, the player may join a game in progress so long as none of the players that started the game have the desired side locked.
The canon ending is confirmed to be Maxis' side of the quest in the official Zombies Timeline.
The Power Lab must be accessed by getting off the bus at the Power Station, near a lamp post and teleporting, or by simply running through the fog. Once at the Power Station, the Power Lab is accessed by opening the door to the outhouse where a secret entrance can be found.
There are three parts to build the switch to turn on the power. One is a circuit, another is a severed arm, and the last is the lever. They are all scattered in this area; collect these parts and assemble a power switch at the blueprint. Then, turn on the power. The lever can be found in the mystery box area on the computer desktops, or it can be by the boxes in the circle at the entrance. The arm can be found by the boxes or when going up the steps into mystery box. The fuse box can be found by the barrier where the player enters, down the first set of stairs, or leaning against a desktop in the mystery box room.
Dr. Maxis' PathEdit
After turning the power on, Dr. Maxis will request the power to be turned off. This must be done after he finishes his entire speech.
Step 5 (optional)Edit
From the Farm, players must travel towards the Power Station area to see the large Electric Tower. In the cornfield on the left hand side of the road, there will be a Pylon. The cornfield is set up as a maze. After killing the last zombie while the lightning is directly above the player, the Avogadro will spawn. At this point, the players should place down two Turbines underneath the Pylon. Dr. Maxis will start talking as the Pylon charges up. When the Avogadro is directly underneath the tower, Dr. Maxis will say: "Finish him now." Players should then use the EMP grenade to kill him while under the Pylon. Alternatively, the Avogadro may be defeated by other means, but the EMP grenade is by far the easiest.
Two players must now pick up their Turbines and go to two different street lamp locations on the map. The first location where Denizens do not attack the player is at the Bus Depot and the second is at the Diner. All four players should now place their Turbines at the same time; two under the Pylon and the other two at the street lamp and the achievement/trophy will be unlocked. (Note: This step can be completed before or after the steps involving the electricity pylon, but only after the power has been turned off.)
After turning on the power, the players need to assemble the Thrustodyne Aeronautics Model 23. There are four parts:
- In the Hunter's Cabin, a shack found in between Town and Power Plant, on the right side of the road when coming from the Power Plant. When inside, it can be found in the fire, on the bed spring, or on the shelf.
- In a building resembling Nacht der Untoten, found in between Farm and Power Plant, on the right side of the road when coming from the Farm. The player needs to follow a small path in the cornfields. It can be found on the shelves that are broken, in the debris, or up the stairs as far as the player can go (not very far).
- In the Tunnel between Bus Depot and Diner. It is commonly found by the barrier. It can be found in between wrecked cars. It also can be found in a corner, where there is a large barrier. Be reminded they are found near the same area in the tunnel.
- A batch of wires found in the same room as Tombstone Soda and the Electric Trap. It can be found when the player jumps down to the ledges. The player must go across the wooden planks and see if it is at the end. If it is not down that way, the player should stay there. He/she now must go across the catwalk to the power generator; the piece should be there.
The Thrustodyne Aeronautics Model 23 must be built in the first floor of the bar in Town. It is good to note that the bus does not stop at the first three locations (and the fourth part may take a bit of time to obtain, so the bus may go away before the players get onto it). Only one player may take the Thrustodyne Aeronautics Model 23.
The players, preferably all of them, must go underneath the Transmission Tower, located on the opposite side of the road of Nacht der Untoten after a small maze in the cornfield. The player with the Thrustodyne Aeronautics Model 23 should shoot it under the tower until it breaks, which is when Richtofen speaks to Samuel. The players now need to kill zombies under the tower. The players must kill zombies with explosives (the Ray Gun counts) until Richtofen speaks to Samuel about the power being too high.
Note: Sometimes when playing multiplayer, Richtofen will yell at Samuel telling him the Pylon needs to be hot, even after firing the Jet Gun until it breaks. This can be fixed by having all players rebuild the Jet Gun again. However this can be very time consuming, especially if one does not know how to navigate through the fog. It's highly recommended to have a player that knows this step and warm up the Pylon under custom games by themselves, and then have everyone join, as this bug doesn't seem to occur when playing solo.
Tip: When doing this solo, it is also recommended to restart the game until the player spawns as Samuel, as Samuel is the only character to tell if this step is done.
A minimum of two players must obtain the EMP Grenade, but it is highly recommended for all four players to obtain them.
Note: Every step before step 6 can be done solo. However a minimum of two people is needed to finish the last step.
At this point, four EMP Grenades should be thrown at four different green lamp posts. These lamp posts can be identified by the green light now emitting electricity and are found all over the map. With four players, this is easily done by everyone throwing their EMP Grenades simultaneously at the lamp posts. However, with two or three players, it becomes slightly more complicated. For one player to throw two EMP Grenades at two lamps, they need to get a Denizen to make a teleporter under the lamp post (done by walking up to the lamp with a Denizen on them), then throwing one EMP on the current position, quickly jumping through the teleporter, and then throwing the second EMP. This method requires teamwork, luck, and both of the two EMP Grenades available. When the EMP Grenades are succesfully thrown, Richtofen happily greets Samuel and the achievement/trophy should pop up.
- The achievement/trophy's name is a reference to the Tower of Babel, a structure that, according to the Bible, was supposed to have been built to reach heaven but was disrupted while in construction.
- The aftereffects of the Easter Egg include the following:
- Maxis' Path: The pylon will glow with orange surges, and occasionally drop power ups underneath it. The lamp posts will have a red aura around them, and they will shoot orange electricity at the pylon. On the world map, the "Green Run" icon will flash with orange lightning.
- Richtofen's Path: The pylon will glow with blue surges, and a power up will drop upon completion. Also, all the lamp posts will have a blue aura around them and will shoot blue electricity at the pylon. Electricity will constantly shoot at the pylon and the red sparks. On the world map, the "Green Run" icon will flash with blue lightning.
- It is also shown that if two people that did different parts play at once, both effects will be visible at the same time.