Wedding planner Lin Wanqing is poisoned at her own wedding, but opens her eyes again in front of the dressing room mirror, with the time rewound to nine o'clock that morning. Trapped in a time loop, she returns to this same dawn with every death, while the killer changes methods each time, waiting for her to finish signing at the quarter-past-ten signing ceremony. Using her professional expertise, she turns the wedding into a crime scene investigation, eliminating those around her round by round. By the twenty-first loop, the groom awakens his memories, confessing that he was planted as a pawn. The truth emerges as her half-brother sets up a double-kill trap to seize the family estate. On the hundredth loop, she uses ironclad evidence to force the true culprit to confess in public, shattering the loop.