What is "The Dark World" in the novel, Warcross?

The Dark World is a virtual reality world built right under that of Warcross. It is parasitic and a place where the black market and criminal activity flourishes. Everything in the Dark World is just a little off compared to Warcross/the real world. For example, the streets do not follow logical patterns, buildings are often placed in the middle of intersections, and trains float through the sky instead of on tracks on the ground. The Dark World also plays host to a great deal of illegal gambling and gang-owned Darkcross games, a more sinister and lethal version of the Warcross Championship that happens in parallel to it. The Dark World is Zero's home base of operations and it allows him to recruit more people to his cause.