Worldview:

In 2022, as climate change melted the Siberian permafrost, an ancient underground aquifer burst during deep drilling for resources. Mutant parasites that had slept since before the Ice Age were released into the world.

Infection Routes:

Oral Infection:

Larvae penetrate the digestive system when contaminated drinking water or animals/plants that consumed it are eaten.

Injection Infection:

When stabbed by an infected host's tentacle, eggs are injected into the body through the ovipositor inside the tentacle.

Penetration Infection:

Adult parasites burrow directly through the skin.

Infection Symptoms:

Early Stage:

Extreme thirst, binge eating, sensation of foreign bodies under the skin.

Middle Stage:

Loss of speech, dark blue veins (movement paths) protruding on the skin.

Final Stage:

Divided into three main types:

Common Type: Reason is destroyed. Adult tentacles protrude from the eyes or mouth. They form swarms by making clicking sounds with their teeth. Driven by spawning instincts, they obsess over water (rivers, sewers, treatment plants), tearing their abdomens open underwater to release larvae.

Mutant Type: Mainly occurs in physically fit hosts. Bones and muscles are restructured. Tentacles burst from the abdomen, ribs protrude like blades, or limbs transform into weapons. Dozens of mutants may fuse to evolve into a wall of flesh.

Mimic Type: Instead of eating the brain, the parasite perfectly integrates with the host's nervous system. Appearance is indistinguishable from humans, and they maintain speech and intelligence. They can understand and mimic human fear and bonding. They pretend to be survivors while secretly spawning in water or injecting eggs into other survivors.

Global Situation:

Europe:

Western Russia and Eastern Europe have been erased from the map (Infected Zones) by swarms crossing the Urals. EU and NATO remnants built a 'Concrete Barrier' along the Eastern European border for a final stand. The Russian government ordered indiscriminate drops of thermobaric bombs and tactical nukes on its own infected cities.

Asia:

Spread through underground aquifers connected to Siberia, smuggled wildlife, illegal loggers, and undocumented immigrants, leading to the collapse of Northern China and the Korean Peninsula. Regular armies and militias either cooperate temporarily or fight for themselves in the chaos.

USA:

Total isolationism. Full coastal blockade and indiscriminate sinking of approaching vessels and aircraft. Internally, a frenzy of searching for the infected is driven by extensive NSA wiretapping and encouragement of citizens to report one another.

Battlefield and Technology:

Weapons:

Guns: Modern automatic rifle rounds can kill Common types, but lack stopping power and may be ineffective against Mutants. Fire: Parasites are extremely weak to fire. Weapons using fire, like Molotov cocktails or flamethrowers, are effective.

Society:

No cure. Upon infection, amputation of the site or execution is the only solution. Doctors are called 'amputation technicians.' Between evacuation notices on smartphones and radios, the government's warning is broadcast repeatedly: "Suspect even your family, report them, burn them."