Live-Streaming My Time Travel Journey Through a Manhole

Ma Tiandong is a retired Marine Corps soldier and former actor in a cave exploration documentary who returns to his hometown of Jiudong City. There, he meets Old Lin, a retired geology teacher and chess master who introduces him to the concept of urban cave exploration. Old Lin reveals a hidden passage beneath the city's pedestrian street, accessible through a manhole cover with a Tai Chi Bagua mechanism. The passage leads to a series of deep, man-made underground caves that absorb light and sound. Ma Tiandong invites Wen Rourou, a former national rock climbing athlete, and Old Zhang, a retired history teacher, to join the expedition. As they explore the nine connected caves, they discover inscriptions dating back to the first year of the Tianqi era in the Ming Dynasty (1621).

The group finds historical records indicating that nine underground caves were dug in Du Guangfu, the ancient name for Jiudong City, by a foreign race. The records also mention strange events where five people jumped into the caves, followed by the death of emperors the next day. During their exploration, the group is sucked into the ninth cave and transported back in time to Du Guangfu in 1621. They are rescued by boatmen and taken to the local prefect, whom they convince of their origin from the future. The prefect helps them locate the cave entrance by tracing historical landmarks.

The four explorers are summoned to the imperial court in Beijing by Emperor Zhu Youxiao, known as the Carpenter Emperor. They are granted titles and tasked with excavating nine underground caves to facilitate time travel back to their own era. While in the Ming Dynasty, Ma Tiandong uses his military expertise to modify arquebuses and single-handedly defeats a Later Jin cavalry force, saving tens of thousands of civilians from massacre. This act earns him the title of Duke Who Pacifies the Nation but makes him a target of political factions, particularly Wei Zhongxian and the Donglin Party.

Ma Tiandong becomes involved in court intrigue and criminal investigations. He receives a mysterious stone figure and is attacked by an assassin wearing an Embroidered Uniform Guard tag. He joins the Northern Garrison Command to solve cases, forming a team with Old Lin, Old Zhang, and Wen Rourou. They investigate a series of crimes, including theft, attempted murder, and homicide, while navigating the complex political landscape of the late Ming Dynasty. The story explores the intersection of modern forensic techniques with historical mysteries, as the group works to uncover the truth behind the caves and their connection to the fall of dynasties.