In this world, human beings undergo the process of birth, old age, illness and death. And when everyone is "born", his "death" is destined. At birth, a "bone" is installed in the lower part of the human heart. Under normal circumstances, the operating period of a skeleton is usually 60 to 80 years. Early or late delays may also occur in many special circumstances. After the running period ends, the skeleton will enter a buffer period. After the buffer period, it will stop operating, and the human heart will also stop beating.
And many things will not be perfect. At some point, some people will be left out and not loaded. This kind of people are "abandoned by human beings" and "drift between humans and gods". The world calls them "mind-catchers". They do not age or die.
The job of the Mindeater is to find undiscovered Mindeaters and lobby them to join the "White Alliance" to prevent them from going astray.
The "White Alliance" is not a secretive organization, but many people will have "normal" evil thoughts, such as escaping and refusing to install corpses, for example - trying to control humans through corpses. Of course, it's the mind-taker's job to destroy these conspiracies.