After fragments of a deadly comet crash in various places around the globe, cosmic particles released from the fragments randomly alter the genetic makeup of any person that comes into contact with them. These cosmic-particle-affected people come to be known as "Comet-Borns" and are looked at as freaks and outcasts by most "normal" people. The Ratkids are a group of orphaned "Comet-Borns" living on the streets of Phoenix, Arizona, and this is an account of their adventures and struggles.