- Disaster name: "The Great Eclipse", which occurred in 2147 and originated from an unknown microorganism that awakened under the Antarctic ice - "Erosion Bacteria".
- Transmission method: Spreads through air and water. It does not directly cause death, but invades the hippocampus of the human brain and gradually "devours" memories.
- Alienation phenomenon: People who have lost more than 70% of their memory will undergo physiological alienation (such as skin covered with translucent bacterial film, limbs mutating into plant-like/crustaceous shapes), which are called "alterants"; a small number of people have weak resistance to corrosion bacteria and can retain some memories, but will periodically experience "memory flashbacks" (seeing fragmented memories of other people or the past), and are called "rememberers".
