You divert the bio‑acoustic‑sonar, its frantic pulse cutting through the crystalline‑black‑frost‑clad corridor as a thin red strobe flickers over the titanium‑bulkhead, revealing a faint, rhythmic thrum of infection spreading like a heartbeat. The helmet’s freezing breath fogs the visor, but the sonar feed spikes, mapping a pulsing node three decks down, its biometric‑distress signature throbbing with alien frost contagion.