Lin Ye, a young man from a village in the city, makes a living by running errands for a watch repair shop. His life is poor but stable, until an old brass mirror he picked up breaks all peace - the mirror reflects a black forest and a three-fingered strange hand that does not belong to him. Amidst the landlord's urging for a rent increase, the strange figure of the old lady on the opposite floor adds to the chill.
A watch delivery mission draws him deeper into the fog: the villa of the mysterious patron "Old Clock" hides the same black forest mural as in the mirror, a strange double-hand watch that beats on its own, a watch repair shop owner with bloodstains on his neck, a three-fingered phantom knocking on the door late at night... All clues point to the half-crescent jade pendant on his chest, and a forgotten past.
"The three-fingered man has been looking for you for three years." The words of the old man in black robe were like a curse. When the owner of the watch repair shop died in a strange manner, and the prophecy of the approaching blood moon oozed blood on the calendar, Lin Ye finally understood that the crescent scar on his chest and the half jade pendant close to his body had already firmly bound him to the mystery abandoned by his mother fifteen years ago and to the existence of three fingers deep in the black forest.
On the way to the west to find the other half of the jade pendant, he not only has to avoid the three-fingered strange shadow that is approaching step by step, but also has to uncover the secrets behind the "old clock" and the retrograde old lady. He also has to face the third shadow of himself that keeps appearing in the mirror - that may be the true identity that he dare not touch. When the blood moon rises and the three fingers return to their positions, the young man who has been knocked on the door by fate will finally find his own answer in the gap between human nature and mystery.
