Nightside is a series of 12 fantasy novels by British author Simon R. Green.
The series is focused on John Taylor, a private investigator based in the fictional Nightside, a dark, hidden netherworld of London in which the supernatural and science fiction super-technology co-exist. Dark, cynical, and humorous, the books offer an adventure into the Nightside, where classic pulp PI novels blend with fantasy and science fiction.[1]