Nothing is ever simple, and nothing ever ends. Feed some drugs to laboratory rats and, two hundred generations down the line, the monsters start being born. The fragile stability of the Dellahan quarantine has been compromised, and something has escaped. Now, a man in the incipient stages of identity-collapse and a dying Bernice Summerfield have to search the byzantine cities of the Proximan Chain for an entity that killed his lover and her friend - an entity that will turn the Chain into its own version of hell.