Lu Yeran is a genius criminal psychologist, but he lost his key testimony from five years ago due to a fire that burned his memory; Qiao Zheliu is a former criminal police captain, burdened with unsolved cases and an anonymous letter - only a burning clock was drawn in the letter. The two are forced to join forces to investigate File No. 7 Of "Crazy Research Room", a secret room game designed specifically for psychopaths. Each time a layer of the puzzle is solved, there is one more corpse in reality, and they are all related to Lu Yeran's forgotten past. When Qiao Zheliu discovered that Lu Yeran's left palmprint matched perfectly with that of the only survivor of the serial case three years ago, the flame of the truth was burning their remaining trust.
