Within the immortal cultivation sects, every full moon, sword shadows detach from their owners, and cultivators subsequently forget their innermost desires. Cen Zhaowei, who has no shadow, hears cries for help from within a sword and discovers that the sect uses seven shadow nails to imprison everyone's shadow thoughts onto the moon gate, stabilizing the mountain gate at the cost of everyone's obsessions. This old covenant traps countless people, and following the clues left by his father, Cen Zhaowei unites with companions, refusing to exchange individual sacrifices for the stability of the mountain gate. Together, they break the old array of forced imprisonment, allowing every shadow to autonomously choose its destination.