Prologue is essentially a tutorial level for players. Unlike most maps, it can only be played on solo. However, a co-op version of the map titled "Gröesten Haus" can be unlocked once the player completes the main easter egg on The Final Reich.
Like Gröesten Haus, there is a secret Mystery Box that can be unlocked within the map. To unlock it, the player must shoot ten lanterns scattered across the map, two of which are outside two windows. When all ten are shot, two doors on the second floor will open, revealing the Mystery Box.
As the player progresses through the waves while in the farmhouse, the level of difficulty increases, with enemies such as the Wüstling beginning to spawn in, starting on wave 20.
The player awakens in the debris field of the train seen in the intro cutscene. Upon crawling out of the wreckage, they find a dying German soldier in front of them, who proceeds to die from their wounds. The player grabs the device on the soldier's belt and activates it, closing the player's wounds as they get up. Walking forward, they see a shovel stuck on a tree stump, with a zombie standing idle in the distance. The player picks up the shovel and approaches the zombie, but another zombie jumps from behind a nearby tree and attacks the player, forcing the player to immediately kill it. Once the jumpscare zombie is dealt with, the player kills the other zombie.
Following the path, the player reads their Notebook before opening a gate to a small farmhouse, where they kill three more zombies. Upon entering the farmhouse, the door closes behind them, where they find another zombie. Upon killing it, the player is tasked with acquiring the MP-40 from the wall. Once the player obtains the weapon, they must acquire at least 2,500 Jolts by surviving in the farmhouse. Once the player gets that total, they can open the door to the right of the MP-40 and leave the farmhouse, ending the Prologue and setting the stage for The Final Reich.