The Zetsubou No Shima main quest remains one of the most intricate storylines in Call of Duty: Black Ops 3 Zombies. Completing the Seeds of Doubt Easter Egg requires thorough map knowledge, proper item crafting, and careful step-by-step execution. Players must navigate dense Pacific island environments, unlock powerful alien artifacts, and repair complex machinery to reach the ultimate conclusion.
Essential Preparation and Wonder Weapon Crafting
Before attempting the main quest, players must power up the facility and assemble fundamental gear like the Zombie Shield and Gas Mask. Acquiring the Skull of Nan Sapwe is mandatory, as its mesmerize ability reveals hidden passageways and vital blueprint details. Additionally, building the base KT-4 wonder weapon and upgrading it to the Masamune provides the firepower necessary to clear organic obstacles and initiate critical encounters.
Locating the Three Elevator Cogs
Repairing the hidden elevator near the bunker entrance requires collecting three missing cogs scattered across the island. The first cog is obtained by shooting down an enemy aircraft using an anti-aircraft gun loaded with a specialized artillery shell grown from blue-water plants. The second cog requires players to electrify their shield, ride the zipline over the lower docks, and drop onto the platform above. The final cog is retrieved by utilizing the Anywhere But Here GobbleGum, which teleports the player directly into an otherwise inaccessible room inside the bunker.
Descending to the Final Boss Encounter
Once all three cogs are installed into the elevator generator, every team member must equip a fresh Gas Mask before taking the lift down. The lower corridor leads to a massive chamber holding a giant, mutated Thrasher specimen trapped behind thick, overgrown vines. Using the Masamune to clear the entrance vines allows players to enter the arena and trigger the primary battle.
Conquering the Boss Battle
The boss fight revolves around surviving waves of Thrashers, spiders, and standard zombies while targeting vulnerable spores on the giant creature. Players must shoot glowing orange spores on the creature's limbs using the Masamune whenever they become exposed. Successfully destroying all four spores ends the battle, triggering the final cinematic sequence and completing the map's main storyline.
