In a small coastal city shrouded in sea fog, the renowned psychologist Chen Yuanshan is found dead in his sealed consultation room. The doors and windows are locked from the inside, the key is in the victim's pocket, and there are no signs of forced entry: a perfect locked-room murder. On the notebook in front of him, a clock is drawn in trembling handwriting. Its hands point to twelve, but the watch on his wrist shows three in the morning. Is this three-hour discrepancy a clever trick devised by the killer, or a clue the victim left behind with his dying breath?
Criminal psychology expert Shen Du is assigned to the investigation. He soon discovers that this respected psychologist had been hiding a secret about lies, betrayal, and atonement for the past six years. And everyone who gets close to the truth loses their way in the fog.
