Written by Simon R. Green
Format: MP3
Unabridged

The series is focussed on John Taylor, a private investigator based in the fictional Nightside, a dark, hidden netherworld of London in which magic and advanced 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.[2]

The novels also contain references to various Folklore as-well-as iconic literature from around the world.

The series itself takes place in a fictional inner city area of London called "The Nightside". Elements of fantasy, science fiction and the supernatural all feature heavily in both the Nightside itself and its inhabitants.

Indicated by its name, the Nightside experiences perpetual night ("it's always 3am"). The Nightside itself is contained within London, yet is larger than London by a significant measure. Though access to the Nightside is hidden, it does experience a steady stream of tourists from the "normal" world.
(Description taken from Wikipedia article at http://en.wikipedia.org/wiki/Nightside_%28book_series%29 )