Completing the main quest on Der Eisendrache stands as one of the most rewarding challenges in Call of Duty: Black Ops 3 Zombies. This ancient Austrian castle holds deep narrative secrets and complex steps required to defeat the Corrupted Keeper. Mastering the sequence early ensures your squad stays ahead of rising round difficulties.
Essential Early Setup and Elemental Bows
Before attempting the main easter egg steps, players must turn on the power and feed the three dragon head statues located around the castle. Feeding these dragons unlocks the Wrath of the Ancients bow from the knight's tomb in the undercroft. Players must then upgrade at least one elemental bow in solo play or all four bows during four-player co-op matches.
Building the Ragnarok DG-4 gravity spikes is another critical prerequisite that should be completed as early as possible. The three required parts drop from killing a Panzersoldat, using a Wundersphere after activating the Death Ray, and surviving a rocket launch test sequence. Having upgraded bows and the Ragnarok DG-4 ensures your team is properly equipped for the upcoming time-travel puzzles.
Navigating Time Travel and Code Sequences
The quest officially begins when players shoot the electrical prongs atop the teleporter using an unupgraded bow to trigger the wisp step. Players must quickly locate and shoot four glowing wisps appearing randomly on items around the map using an upgraded bow. Successfully completing this sequence turns the teleporter pad purple, allowing the team to travel back in time.
While in the past, one player must observe Dr. Groph inputting a combination code on a wall safe while another grabs the fuse and soul canister. After returning to the present, input this exact code into the computer terminal near the clocktower to unlock the undercroft safe. Retrieving the Tesla coils and information disk allows you to activate the Death Ray console and trigger the Simon Says memory game.
Escorting the Keeper and Soul Collection
Once the death ray pod crashes into the courtyard, collect the golden Vril device and insert it into the knight's tomb. A spectral Keeper will spawn and begin moving to four distinct locations across the castle. At each stop, a glowing circle appears on the floor requiring players to collect zombie souls using specific elemental bows.
The color of the aura surrounding the circle indicates which upgraded bow must deal the killing blows to charge the Keeper. After all four locations are fully charged, place the blue soul canister into the missing slot on the MPD pyramid. Ensure every player is fully restocked on ammunition, perks, and GobbleGums before initiating the final teleportation to the boss arena.
Defeating the Keeper Boss and Ending the Quest
Inside the boss arena, players must dodge waves of skeletons, Panzersoldats, and deadly area-of-effect shockwaves from the massive Keeper. When the central area glows yellow, a player must slam down the Ragnarok DG-4 spikes directly underneath the boss to trap it. Once trapped, all players must unleash concentrated fire into the glowing chest emblem until the phase ends.
Repeating this trap sequence three times will defeat the Keeper and send your team back to the castle pyramid room. Interact with the MPD to acquire the Summoning Key, then place it into the main computer terminal near the clocktower. Triggering this final console initiates the epic ending cutscene and unlocks the official map completion trophy.