Imagine Harry Dresden loose in a Neil Gaiman-style world, and you'll have some idea of what's going on in the world of the Nightside.
And "Into the Nightside" introduces us to the first two fantasy-noir adventures of Simon R. Green's strange, creepy other-London. The first book in here starts a little shakily, but once Green finds his footing the story rolls along with a few slow spots, theological fast-and-looses, and the occasional moment that is just too weird for words.
John Taylor fled the Nightside years ago, and set up shop as a PI in London, using his special talent (finding things) to eke out a living. But when wealthy Joanna Barrett hires him to find her teenage daughter, Taylor finds himself leading her into the Nightside, and acquainting her with the terrifying, often gruesome chaos that dwells inside it.
Then they accidentally step into a timeslip, and John finds himself facing a ruined, dead world. Worse, it turns out HE was the one who did it, many years in the past. Tormented by this possible future, John must find the girl who was lured into the Nightside -- and hope that the area doesn't get blown up first.
Amidst strange angel rumors, John Taylor is hired by the Pope's undercover representative, Father Jude. The Vatican wants to hire Taylor to find the Unholy Grail -- the cup that Judas drank from at the Last Supper. Think the One Ring in cup form. So John and Shotgun Suzie prowl through the Nightside, into devil S&M clubs and neo-Nazi halls -- but the angels and demons have landed in the nightside, and will rip it to shreds to find the Grail.
The first half of the first book is basically an introduction to the horrors and wonders of the Nightside. Even if Simon R. Green had no writing ability whatsoever, the world he conjures in the Nightside series would be worth the read -- dripping with darkness, eccentricity and utterly twisted fantasy-noir humor. And boy, is it fun.
But after that, Green's mystery stories get solidly entrenched into a nice noir groove, although it usually takes him awhile to get the plots moving. His writing has a dark, wry snappiness, with plenty of solid dialogue ("Suzie doesn't know the meaning of the word 'fear.' Other concepts she has trouble grasping are 'restraint,' 'mercy,' and 'self-preservation'") and tongue-in-cheek occurrences like the buried ghost of Merlin.
The generically-named John Taylor is a good noir hero too -- he's got a very mysterious past and a lot of people out for his blood. The first book unfolds a devastating possible future, and the following stories give more hints about who his unknown mother is, and how he could be such a threat to the entire world and everyone in it.
Some of the other characters are not quite what they seem, but Taylor bumps into some endearingly bloodthirsty characters (like Razor Eddie and Shotgun Suzie. Guess what they do for fun) and occasionally someone halfway normal like Taylor's teenage secretary.
"Into the Nightside" brings together the first two Nightside books, and takes readers into a grotesquely fascinating world full of everything you don't want to dream about. Despite a few bumps in the road, it's a nice, dark read.