> While clearing out old belongings in high school, Su Wanqin finds a hairpin decorated with a red spider lily, left behind by her mother.
> The copper pin is stained dark red, and the white-bone carving at its end feels icy to the touch.
> The night she puts it on, her mother's reflection appears in the mirror: "Don't take it off..."
> The classroom clock begins to run backward, and unfamiliar words appear carved into a desk: "You're next."
> Terrified, she pulls the pin off, but its bone tip cuts through the air, leaving a streak of blood.
> Pale blue fingers reach through the crack, accompanied by the laughter of students from a mass disappearance case thirty years ago.
> As her homeroom teacher writes with his back to the blackboard, she sees the same red spider lily tattoo appear on the back of his neck.
> A long-sealed file in the school history archive records that her mother was the only girl who refused to wear the hairpin.
