The back hill of Mingde Middle School has always been a "forbidden area" in the eyes of students. It is overgrown with weeds and rarely visited by people. Transfer student Lin Xiaoman accidentally got lost and discovered a hidden wooden tree house in the dense camphor forest. This treehouse seems to hide many secrets. The yellowed diary, mysterious symbols, and looming lights in the middle of the night all make Lin Xiaoman curious about it. As the exploration deepens, she not only meets Jiang Yu, a top student who is also interested in the tree house, but also gradually uncovers the connection between the tree house and a campus incident twenty years ago. A story about youth, secrets and growth unfolds.
