Wu Shijie, a loner, disappears after leaving Yin An a mysterious phone message.
Yin An had no connection to him, but the clues all point to her being closely tied to Wu Shijie's disappearance. Before long, Yin An disappears too.
While investigating, police officer He Jin stumbles across a secret organization hidden in the town, with a vast underground network.
Yin An reappears with a secret of her own. She decides to join forces with He Jin to find Wu Shijie and obtain evidence of the organization's crimes.
But Yin An's parents repeatedly try to stop her. Could they also have some connection to the mysterious organization?
Defying He Jin's objections, Yin An resolutely goes undercover and infiltrates the enemy's ranks.
A complicated past, a tragic fate, a mysterious disappearance, hidden secrets... As the investigation deepens, the truth gradually comes to light. What will ultimately become of Wu Shijie?
And what is the true face of this mysterious organization?
