Prosper City is where it all had begun. In the year 2200, a mysterious hole appeared in the center of the once thriving city. Through it, demonic beings referred to as "Passers" have been able to freely enter into and wreak havoc on human society. In order to deal with these unwanted fiends, the organization PEX, or Passers Exterminators, was formed. This is the tale of one of their officers.