In 1825, a plague swept the world. People have not yet found a cure for the plague. Because the bodies of those who died from the disease were rotting and turning black, they were called black natural disasters. Fifteen years later, in 1840, it was discovered that this natural disaster was related to a missing saint and the murdered Mengsha, and an investigation was launched. During the investigation, Norante and his party encountered an assassination attempt by the cult at night. Before she died, Nelua turned on her pocket watch and traveled through time and space back to the past. And after each change, the timeline has also changed...
