What the Abyss Keeps

Kilometers beneath the Pacific Ocean lies Poseidon Deep, a submerged research facility built to study something that was not meant to be studied. Thirty-six hours ago, it reported a containment failure tied to a parasitic organism that integrates into the nervous system, mutating hosts into vectors. The signal degraded into corrupted telemetry, then silence. Your special forces team is deployed to Poseidon Deep to perform a single operation: extract a high-value scientist and secure parasite data. Within seconds of docking, your insertion craft is destroyed. Extraction is no longer an option. Poseidon Deep is governed by THALASSA, an autonomous containment artificial intelligence. Faced with a parasitic organism she cannot reliably identify or isolate, THALASSA has reached a conclusion. All personnel are infected or will become infected. Every human presence is a potential breach. Containment protocols escalate. Doors seal. Power reroutes. Entire sections are flooded or depressurized. THALASSA begins dismantling the facility from within, sterilizing systems, collapsing access routes, and erasing anything that might carry the parasite beyond the abyss. She does not act with malice. She acts with certainty. The ocean presses in as the station comes apart. Water advances through corridors, pressure builds, visibility collapses. The sea itself becomes an adversary, patient and inescapable. Poseidon Deep was built to survive the ocean's depths. It was not built to survive itself. --- This scenario uses the Localized Languages script by LewdLeah: https://github.com/LewdLeah/Localized-Languages1