Welcome to the Demi-Monde. In the year 2018, the Demi-Monde is the most sophisticated, complex and unpredictable computer simulation ever created. Rees’ book is one of the most entertaining alternate reality/sci-fi books created in some time. Rees populates the Demi-Monde, originally designed as a military training ground, with some of the worst villains from history. We enter the Demi-Monde in search of a missing person, who is stuck in the simulation and cannot get out. Once I started reading, I didn’t want to leave.