Four young people (a man with a head full of weird ideas, a highly educated woman with an arrogant nature, a lazy man who loves face, and a woman who worships money) have difficulty integrating into society due to personality reasons. They suddenly came up with a whim and built a "historical... Mythology Detective Agency" specializes in exploring some mysterious events in ancient history. By chance, they accidentally discovered the Qin Emperor's Mausoleum built on the seabed, uncovered the mystery of the Ming Dynasty's Apocalypse Explosion, found the lost Yuan Dynasty Emperor's Mausoleum in Qichao Valley, and discovered the mystery of Empress Wu Zetian's wordless monument , witnessing the truth behind the violent death of Song Taizu Zhu Ying with the sound of an axe... Of course, this adventure is not all smooth sailing, especially when these four young people with outstanding personalities come together and develop a series of romantic relationships with various weirdos. In the end, this group of young people discovered that there is a mysterious clue hidden in all historical mysteries, and all clues point to a shocking secret related to human life and death. In order to save the world, "Historical Detective" must travel through life and death to explore the mysteries of the universe and the origin of mankind, and realize the ultimate dream of mankind.