In the corner of the ancient city where the boundaries between yin and yang are blurred, there is a "Wangchuan Inn" that is only open from midnight to dawn. On the surface it is an ordinary inn, but in fact it is a transfer station for "Huangquan Express". The owner of the inn (or special employee) can receive the "ghost package" from "that side" that contains unresolved obsessions, and entrust it to a specific (usually desperate or special-fated) "Earth Runner" to deliver the package to the designated person in the underworld. Signing for the package means that the last wish of the deceased must be fulfilled (it may be to send a message, bury something, teach someone a lesson, protect someone, etc.), Otherwise it will be contaminated with bad luck. The inn itself is also a spatial node, connected to some special "roads to the underworld".
