Shen Yao is trapped in the seven-day cycle before Lin Shu's death.
The bell in the old laboratory building is the death knell, the dark shadow on the rooftop is the executioner, and Lin Shu - the one who was killed
The boy who is regarded as a ghost by the whole school always stops breathing in different ways at dusk on the seventh day.
Purpose: When obsession transcends the dimension of time, martyrdom becomes the sharpest self-destructive weapon