Introduction: Deputy Captain Li Kaiyang of the major crimes unit teams up with his reluctant apprentice Jiang Han to crack a series of sexual assault cases and a bizarre naked-body murder. But then a falling-death case emerges, and the supposedly gunned-down "Red Gloves" mysteriously returns to life, unleashing more horrors. Piece by piece, a decades-old puzzle comes together, thanks to the master-and-apprentice duo's relentless sacrifice.