After picking up Zhang Qiling, Wu Xie's headache did not subside. Zhang Qiling was often missing when he was in Yucun. A text message from Wang Meng broke the originally peaceful life. A letter sent to Wu Shanju pointed to a long-abandoned mental hospital in the northeast.
This is a trap aimed at Wu Xie.
The hexagonal brass bell appears again. What secrets does the person behind it want to find out?
Who is the sender? Who is the person who set up the trap? What is it that keeps Wu Xie awake?
Concept: Dessert