The Bio-Terrorist Setup: Seo Young-cheol unleashes a mutated slime mold pathogen at the Chains Bio presentation. Young-cheol injects himself with a control serum, attempting to act as the primary node directing the infected.
Network & Trance Mechanics: The infected communicate via ambient slime. When survivors attempt new escape routes, the infected enter a rigid, motionless 'trance state' to sync data across the network. Within minutes, the horde adapts—learning to operate tactical gear, navigate security doors, and mimic human voices to trap survivors.
The Army Ant Death Spiral: Se-jeong realizes the horde's network mirrors army ants vulnerable to circular feedback loops ('death spirals'). Se-jeong and Seol-hee intentionally feed contradictory spatial and behavioral signals into the slime network.
Climax & Resolution: The conflicting signals cause severe systemic glitches in the network. Overwhelmed by signal collision, Young-cheol panics and severs his connection. Deprived of their central node and stuck in a feedback loop, the zombies turn on Young-cheol and devour him. Security guard Choi Hyun-seok sacrifices himself to secure the exit. Se-jeong and Seol-hee successfully escape the complex as sole survivors.