It’s the year 3050, a millennium since the most catastrophic event in history. A meteor the size of the Pacific Ocean hit Earth, incinerating the land and all living things. Humans are extinct, and only a few artifacts remain as proof of their existence. Recently, an alien civilization discovered Earth, and they have been studying the human species using only the ruins as scientific evidence. One of the last pieces of literature is a diary written by a 15-year-old named Cassette.