Recreating the Year of Peace: Young People's Journey on the Xunyang River

Li Jun, an adventure enthusiast in the 21st century, accidentally traveled to the Northern Song Dynasty 1,000 years ago due to an outdoor adventure, and possessed the body of a boy, also named Li Jun, who was an ordinary fisherman boy by the Xunyang River. After Li Jun woke up, he found that he was facing a life and death crisis. Who was the murderer?