The "Crime-Solving Duo" Huang Xiaochuan and Shen Xuexin stumble upon a murder case on a rainy night during graduation season. A penniless college student and a wealthy heiress team up to solve a bloody hotel murder, only to uncover a string of connected cold cases. When they open a private clinic specializing in "psychological profiling + forensic examination," an ordinary-looking case leads to the truth behind an old case from fifteen years ago. A lipstick mark on a coffee cup, skin under the victim's fingernails, ten seconds missing from a surveillance video: every detail becomes damning evidence that overturns false testimony. As the shadow of a mysterious organization gradually looms over them, they discover that every case points to a carefully laid revenge trap...
