In a previous life, on a stormy night, Su Yuqing had a conflict with her stepfather and eventually left both her parents' homes. With nowhere else to go, she asked Chen Mo if she could stay at his house. Chen Mo refused, and she was murdered in an old alley on a street corner that same night. As an adult, Chen Mo spent years reviewing case files and interviewing people connected to the case, but he still couldn't find the killer. Then he returned to the stormy night ten years before the murder. This time, he let Su Yuqing inside and agreed to let her stay temporarily. As the time of her murder in his previous life approached, he went alone to investigate the old district.