The Thirteenth Rule

Xihe Tower is an old office building with elevators. On the surface, it runs normally, with people coming and going every day.

But the building has a set of invisible rules: thirteen of them. The handwritten, posted, and spoken versions contradict one another. Anyone who breaks the rules will be "replaced": their appearance stays the same, but their behavior shifts in subtle ways, and their shadow falls out of step with their body. Those who have been replaced never admit it.

Investigative reporter Yu Hang went undercover in the building and disappeared, sending back only one incomplete message: the thirteenth rule failed to send, leaving only half a gap.

His partner, Lu Wen, enters the building as an outside reporter, carrying that message. He has three things with him: a press pass, a broken communication log, and an obsession with refusing to believe his partner is gone for good.

He must pick out the replaced person from a crowd of living people, and that person could be right in front of him, unrecognizable to everyone.

The rules always have loopholes. His partner is somewhere in the building. And Lu Wen's own name has begun to appear at the edge of the list.

He dares not break the rules, and dares not trust anyone.