Complete the following steps in The Final Reich (Zombies) to complete the Easter Egg (retrieve the Artifact) and get the "Fireworks" trophy.

Note: To make completing the Easter Egg easier, keep pressing the Touchpad button on your controller to highlight most of the objectives in-game. It can be completed solo offline or with any number of players in co-op.

Step 1 - Turn on the Power: There is a generator in the middle of the map with three red lights on it. Your objective is to make all of them green. To do this, turn three gas valves around the map for about six seconds each. The first one is located behind the Geistschild machine in the village square area. The second one is also in this area to the left of the bunker door you are trying to open. For the third one, open the door towards the pub. You can simply look for the power cables connecting the generator and the gas valves on the floor. Just follow them to all the respective valves. Once the generator is working again, activate the flamethrower trap in the middle of the town square to destroy the wooden lid covering the entrance to the sewer area. Go down there and proceed down the only path you can follow to see the actual power generator for the map on the left side next to the exit. Interact with it to turn it on.

Step 2 - Rerouteing the Power in the Bunker: Once you are in the bunker, buy the doors to the morgue and laboratory for 1,500 jolts each. Then, activate two different control panels within 30 seconds. One is in morgue and the other is in the laboratory. The morgue one is just down the set of stairs on the right (when entering the area). The laboratory one is on the second floor, above the Schildblitz machine. Once the power has been rerouted, buy the door in the middle of the command room to the salt mine tunnels.

Step 3 - Power up the Geiskraft Transfer Device: Proceed down the mine until you reach "The Emperor's Chamber" large circular room. This room is where most of the objectives will take place in, as it is your task to retrieve the Artifact from this machine. Interact with the device. Then, kill approximately 15-20 zombies to charge the machine. All zombie types count for this. Once it is powered up, the next objective is to unlock the canopy that is blocking the device. To do that, simply return to the command room and turn the crank in front of you by interacting with it. Next, start the Tesla Gun assembly process. Simply walk up the stairs in the command room and interact with the red button in front of you.

Step 4 - Assemble the Tesla Gun: To get the two missing parts for the Tesla Gun, first escort the Geistkraft Device into the laboratory. There is a red area around the device, and you have to kill zombies within that area to make it move. Once you have reached the end of the escort, the device will stop and power up a generator. Simply wait approximately 45-60 seconds for the generator to finish. You can then collect the Tesla Gun barrel. After the device has moved back to the command room on its own, you have to escort it again by killing zombies in the red area, but this time it will move to the morgue. Once it is there, you have to wait 45-60 seconds again for the giant blender to finish. Once you have collected the Tesla Gun core, go back to the command room and place both parts in the weapon forge (be careful though as a powerful Brenner zombie will spawn first -- make sure to use a decent wall weapon for this part). You can then collect the Tesla Gun, which also unlocks the "Lightning Handler" trophy.

Step 5 - Power up the Right Hand of God: Go to The Emperor's Chamber again, and interact with the Right Hand of God (machine to the left when you enter the room). Then, go back up to the command room and activate the large control panel behind the weapons forge. Your objective now is to activate the smaller fuse boxes 1 to 4 in sequence and to change the color of each display to the one you saw on the control panel. The three colors are Rot (red), Grun (green), and Blau (blue). You have around 45 seconds to activate all four boxes -- so you will have to quickly memorize the four color sequence, change the first display to the respective color, and then make your way over to boxes 2-4. They can be found at the following locations:

1. Next to the main panel.
2. After going through the morgue and the door leading to the sewers, it will be in front of the Pack-A-Punch machine room, at the crossroads.
3. Next to the door leading out of the Pack-A-Punch room to the harbor.
4. Next to the door leading to the tower from the pub.

Your next objective will be to go over to the tower and activate and defend the central lightning rod. This should be fairly easy if you use your special ability. Once this has been completed, activate and defend the two smaller lightning rods on the left and right. This can be a bit difficult solo, but should be fairly easy with a 2-4 players. Just keep checking both rods frequently and kill the zombies as quickly as possible. Make sure to be careful since another Brenner spawns once this step has been completed.

Step 6 - Repair the Left Hand of God: After interacting with the Right Hand of God, a zeppelin will spawn outside, flying in circles over the town. Shoot one of the four orange lights on the bottom of the zeppelin until a "Uberschnalle" (battery) is dropped by the ship. To do this, focus on one of the four lights and damage it until it is red and eventually drops the Uberschnalle. Run over to the location it was dropped to ensure the ship does not steal it back (which would force you to damage the zeppelin again). Then, get kills near the Uberschnalle to charge it up. Once it is fully charged, take it down to The Emporer's Chamber and place it in the Left Hand of God. You might have to use your camouflage ability to carry it down there or drop it multiple times, as zombies will be attacking you. Repeat this step two more times. If the objective tells you to survive until the zeppelin returns, you have to end your current round or else the ship will not spawn again. Once you place the third and final Uberschnalle, the Hand of God will now be working.

Step 7 - Calibrate the Voice of God: The Voice of God is the machine between the Left and Right Hand of God. To calibrate it, change the four numbers below the raven symbols on the side of the machine to their correct number. To find the correct number for each raven, scan four portraits around the map, using a Brenner head. At this point, you should have already killed two or three Brenners. Go back to the spot where you killed one and grab their head. You can also click the touchpad button to highlight the heads. To scan a portrait, simply hold the ADS (aim down sights) button. You will see a roman numeral next to the raven. The numbers go from 1-5. The four portrait can be found at the following locations:

1. Moonraven (moon above his head, facing forward): On the lowest floor in the morgue, on the opposite side of the sewer door.
2. Stormraven (facing right): Inside the pub on the second floor.
3. Deathraven (facing forward): Inside the Pack-A-Punch room.
4. Bloodraven (facing left): Outside of the church, near the M1928 wall weapon.

Once you have figured out the four numbers needed, enter them into the Voice of God machine and activate it.

Step 8 - Defeat the Panzermorder (Klaus): A red electric bubble will appear above the Geistkraft Transfer Device in The Emperor's Chamber. Shoot it with the Tesla Gun to make it open up. You can now see the sword hilt sticking out of it. Collect it to start the Panzermorder (Klaus) boss fight. The fight consists of two steps that you have to repeat three times. The steps are:

Step 8.1 - Get a Uberschnalle from the Zeppelin: This is exactly the same as Step 6. Follow Step 6 to complete it.

Step 8.2 - Attach the Uberschnalle to the Panzermorder (Klaus): Shoot Klaus until you have stunned him (the game will tell you when you have successfully done that), then attach the Uberschnalle to him. Once you have done this for the third time, the boss fight will be completed.