In the book, narcotics officer Calexico (named after the place Calexico) Moore's body is discovered on Christmas night in a seedy Hollywood motel, from an apparent suicide. It was rumored that he had been involved in the selling of a new drug called "Black Ice". As the L.A. police higher-ups converge on the scene to protect the department from scandal, Harry Bosch inserts himself into the investigation. The trail he follows leads to Mexican drug gangs operating across the border, while he gets attracted to Calexico Moore's widow as the case progresses.
The "Black Ice" drug is a fictional drug invented by Connelly for his novel.