A murder case in an abandoned watch factory opened up old scars from twenty years ago - factory director Shen Jingyan was found dead under a stopped pendulum. His pocket watch chain was entangled with strange gears, and the hands were always fixed at 3:17 in the morning, which was exactly the same time as the fire that burned down the factory.
Interpol Ji Yanli intervenes in the investigation, but is surrounded by layers of fog: traces of thallium in the body of the deceased, neurotoxins in the eyeballs, mysterious tapes hidden in secret rooms, and seven copper gears engraved with "a promise that will never fade", all point to a conspiracy buried by time. Su Fanyin, the daughter of the deceased, suddenly appears. The old notebook she carries contains clues that are surprisingly consistent with the case - the mystery of the "seventh gear" left behind by her father before his disappearance, and the sentence "Never trust someone who wears a gear ring."
As the investigation deepened, seven core members of the factory had accidents one after another, and each person's death was closely linked to gears, clocks, and time. The hoarse male voice on the tape, the crazy words in the mental hospital, and the secret displays in the old town clock shop gradually pieced together a terrible truth: the fire twenty years ago was not an accident, but an attempt to cover up a secret that could subvert everything.
Ji Yanli and Su Fanyin are torn between suspicion and trust. They must unravel the curse behind the gear before the death prediction of "002 is next" comes true. When promises and betrayals began to reverse on the ruins of time, they discovered that the most dangerous gears might be hidden in each other's memories.
