What are the motifs in Neverwhere by Neil Gaiman?

Morality and free will are recurring ideas in the story. In Neverwhere, morality is depicted both in stark contrast and in shades of gray. Mr. Croup and Mr. Vandemar, for example, are essentially demons in human form. Though they are also professional killers, limited by their contract for hire, they glory in death and destruction for its own sake. Never is there a sense that these two could be anything other than what they are. They are exemplars of evil.