Call of Duty: WW2‘s take on Nazi Zombies arguably provides the least confusing Easter Egg in the series to date, thanks to a list of objectives that should keep players on the right track. However, there’s actually a second, far more complex Easter Egg for players to complete that fans have dubbed the “hardcore” Easter Egg.

As its name suggests, getting the hardcore Easter Egg in Call of Duty: WW2 is no walk in the park. Players will need to go into it with solid loadouts and a deep understanding of The Final Reich map if they hope to survive. Once players have thoroughly familiarized themselves with The Final Reich map and its layout, they can give this incredibly challenging Easter Egg a shot.

For those that would prefer to use a video guide, we recommend this one by PowerPyx:

Step 1: Build the Tesla Gun

Like with the casual Easter Egg, the first step to completing Call of Duty: WW2‘s hardcore Easter Egg is building the Tesla Gun. Building the Tesla Gun is a multi-step process in and of itself, so please refer to our Tesla Gun guide for more information on that front.

Step 2: Complete Most of the Casual Easter Egg

The early steps for the Dark Reunion Easter Egg play out exactly like the steps players had to complete to unlock the Fireworks achievement/trophy. Players need to reach the point where they have to shoot the orange orb in the Emperor’s Chamber using the Tesla Gun. However, shooting the orb triggers the boss fight and will make players get the casual ending, so it’s important that no one shoots the orb at this time.

Step 3: Upgrade the Tesla Gun

call of duty ww2 tesla gun zombies sledgehammer activision

At this point in the Easter Egg, players will want to take the time to unlock all of the upgrades for the Tesla Gun. Please note that this is a long and tedious process that forces players to advance multiple rounds in order to get all the upgrades.

The gist of it is that players first have to complete some obscure objectives to obtain batteries, which then have to be powered by killing specific zombie types near it using the various traps around the map. Just like building the Tesla Gun is an exhaustive, multi-step process, so too is obtaining all the upgrades for it, and so we urge anyone having trouble to refer to our Tesla Gun upgrade guide for additional help.

Step 4: Red Talon Sword

Next players will want to obtain another powerful weapon in the game, the Red Talon sword. As one might imagine, getting the Red Talon sword is easier said than done, but the quick version is this:  flip the power switches in the Laboratory, Morgue, and Command Room to reveal coils in the Command Room. Shoot the coils with an upgraded Tesla Gun to open hatches in the entrances to the Laboratory and Morgue.

A couple of safes are found inside these hatches, so shine a Brenner head at their dials and turn the dials to find purple thumbprints. Finding all the purple thumbprints will unlock the safe, allowing players to grab the item inside. Proceed to the next round and then repeat the process for the other safe. With both items in tow, go to the statue at the back of the Emperor’s Chamber, use it, and then turn the coin-like object to get the sword.

Step 5: Find the Tops

Call of Duty: WW2 Zombies Dark Reunion Easter Egg Guide - Nazi Zombies toy shop

This step is tricky because players have to find three tops that will spawn randomly in different locations around the map. When playing in a group, the best bet is to have someone keep a zombie distracted while other players search the map for the tops. Check the rooftops in the Courtyard, Pub, Riverside, and Village Square areas for green, red, and yellow tops. Shoot them down, pick them up, and then deliver them to the toy display case near the Command Room entrance.

Now check all the windows in the outside areas of the map to find enigma coding machines wrapped in colored ribbons. The ribbon colors will correspond with one of the colored tops at the toy shop. Find at least two of these enigma machines (like the tops, they spawn randomly), and write down their ribbon color and number. The numbers equate to different times, so spin the tops until the arrow on them point in the direction the number would be on a clock face.

If done successfully, a record will pop out of the bottom of the toy shop window. Be sure to grab it before proceeding to the next step of this increasingly elaborate Easter Egg.

Step 6: The Voice of God

Call of Duty: WW2 Zombies Dark Reunion Easter Egg Guide - Chandelier

Yet again, players need to search the map for something that will spawn in random locations, and this time they’re looking for a weather vane. Shoot the weather vane and it will point in the direction of a strange glowing light. Shoot this light, and then the water wheel near the Pack-A-Punch room will stop spinning, revealing coils. Shoot the coils with upgraded Tesla Guns, and then go to the dilapidated house where the increased weapon damage perk is located.

Place the record inside the gramophone here and stay by it, killing zombies to power it up. Once enough zombies have been killed by the gramophone, players will hear an audio code. Quickly jot that down and then head through the Salt Mines and down into the Emperor’s Chamber. Approach the Voice of God machine and input the numbers in order, from the right dial (facing the machine) around to the left side. If it doesn’t work, try inputting the numbers in the opposite direction. When done, press the button on the center of the machine.

Now aim at the chandelier in this room and shoot it with all four Tesla Gun upgrades. When that’s done, the orange orb in the middle of the room will turn blue. Everyone needs to shoot the blue orb simultaneously with upgraded Tesla Guns. If done successfully, players will be able to collect Barbarossa’s hilt, triggering a cut-scene.

Step 7: Boss Fight

Luckily for those that have already completed Call of Duty: WW2‘s casual Easter Egg for Nazi Zombies, the boss fight in the hardcore version of the Easter Egg plays out exactly the same. Players simply need to shoot batteries down from the blimp, charge them with zombies, stun the boss, and place the batteries on him. Repeat this process three times (remember that the battery will retreat to the blimp on the third attempt) and then players will unlock the final cut-scene.

Once the Dark Reunion trophy/achievement has been earned, players will have successfully completed the most difficult challenge in all of Call of Duty: WW2. However, anyone that has been a fan of the franchise and its Zombies modes should know that even greater challenges lie ahead. The game’s first DLC pack, The Resistance, is due out in early 2018, and will likely bring with it a new Nazi Zombies map for players to tackle after they’ve conquered The Final Reich.

Call of Duty: WW2 is available now for PC, PS4, and Xbox One.