After a century of stability, Hogwarts’ wards begin to fail when a tremor cracks the Black Lake, releasing a new, virulent strain of Inferi. Unlike the mindless dead of old, these creatures spread a “cold rot” that infects the living, turning the outbreak into a fast-moving contagion within the castle. As students are injured and begin to change, Hogwarts collapses into chaos. The Great Hall becomes a triage center, evacuation efforts fail, and the Ministry seals the school under strict lockdown—treating everyone as a potential carrier. What starts as something rising from below quickly becomes a containment crisis from within.