Nightside (book series)

Nightside is a series of twelve fantasy novels by author Simon R. Green. Green states on his site, regarding "The Bride Wore Black Leather", "This is the last Nightside novel featuring John Taylor and friends and the last Nightside novel for the time being."
At the end of the Secret Histories novel, Moon Breaker, the final page says "Shaman Bond and John Taylor Will Return in Night Fall."
Setting.
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.
The novels also contain references to various folklore and iconic world literature.
The series itself takes place in a fictional inner city area of London known as the Nightside. The Nightside experiences perpetual night ("it's always 3am"). The Nightside itself is contained within London, yet is significantly larger than London itself. Though access to the Nightside is hidden, it does experience a steady stream of tourists from the "normal world".
The series' protagonist John Taylor describes the Nightside as "a place where dreams come true and nightmares come alive. Where one can buy anything, often at the price of your soul... or someone else's. Where the music never stops and the fun never ends". Numerous seemingly impossible services or goods are available such as albums from alternative time-lines (e.g. a live Mama Cass concert from 2003), a business where customers pay to be possessed for a brief period of time "just for the kick of it," and a drug called Revert which causes users to temporarily devolve into a biological ancestor (e.g. a Neanderthal).
A recurring feature in the Nightside is the appearance of "timeslips", locations where the Nightside collides with another part of space and/or time, and sometimes with a completely separate, alternate timeline as well. A number of characters identified within the series are "refugees" displaced by timeslips. The appearance of timeslips is generally, though not always, unpredictable and unplanned.
The Nightside is overseen by the Authorities, a committee whose members are largely unknown which makes rules, policy, and decisions concerning what is allowed to happen within the realm. The Authorities' decisions are enforced by their Agent (or "the Man"), who among other equipment and abilities is given the Voice, a way of issuing vocal commands which no human can refuse. At the beginning of the first book this position is held by Walker.
Main characters in the series.
The main character of the series, John possesses a supernatural ability to locate anything, which he refers to as his "private eye". This allows him several secondary abilities, such as disrupting magical forces and wards by finding and removing the lynch-pins that hold them together. Before doing these things, he utters one of his catchphrases: "...and it was the easiest thing in the world to...!". He later learns to relocate certain objects, such as unloading enemy weapons at a distance, removing cavity fillings, or removing the air from someone's lungs. Taylor is the son of Lilith, who first created the Nightside. This fact has made Taylor a primary target for many powerful forces, who wish to aid or kill him depending on their opinion of his mother.
The Nightside's most dangerous bounty hunter, named for her trademark pump-action shotgun. Known for bringing back her bounties dead because, as she always puts it, "it takes less paperwork". Later in the series, she reveals to John that her older brother raped her and made her pregnant when she was a teenager, forcing her to have an abortion. After she murdered her brother, she disappeared into the Nightside. Later in the series she and Taylor become lovers. Introduced in the book as "Suzie Shooter, also known as Shotgun Suzie and "Oh Christ it's her, RUN!""
A former gang member who made a deal with someone or something he refuses to name on the Street of Gods and came out a God, Razor Eddie is now a vigilante for the good (and the Good don't get a say in it). He is known for prowling the streets and killing bad guys with his trademark straight razor. In later books, he reportedly returned to the Street of the Gods and, as he puts it, "got an upgrade" which allows him to use his straight razor to open portals between places and even dimensions. Razor Eddie is also mentioned in another of Green's series', "Hawk and Fisher", as a well-known street fighter turned vigilante from the Street of the Gods. Eddie's pearl-handled straight razor is purportedly the only thing that can end his immortality and is on par or below power with the Walking Man when he has his razor.
The public face of the "Authorities". Was a good friend of John's father. Most of Taylor's cases in the Nightside are due to him. He is known for using "the Voice", allegedly given to him by the Authorities, which forces people to do what he wants and can even bring the dead to life so they can answer his questions, although there are a few members of the Nightside that can defy or outright ignore his "Voice". After the death of the Authorities, no one knows who powered his voice but he claims that it's powered by the same voice that said: "let there be light". He's later seen on a quest with Eddie Drood from "Secret History" series.
Also a friend of John's father, the Collector is an obsessed collector of the rarest artifacts known to exist. He lives in seclusion, away from the rest of the Nightside, and frequently changes the location of his lair. Less of a friend than an enemy to John, but still offering his help on a few occasions, some of which was invaluable to John, the Collector's personality is somewhat of an enigma. His key interest is adding to and protecting his private collection.
The current owner of Strangefellows, an irritable young man always dressed in black (only because there is no darker color). Taylor goes to him for information and meets clients at the bar. His sour behavior has something to do with the fact that Merlin Satanspawn, his direct ancestor, put a curse on the bar so that he can only leave if another member of his family takes his place—and apparently he's the last of the Morrisey family. Has something of a grudging friendship with Taylor, as after Taylor was ambushed outside the bar, Alex granted him a special "back to bar" teleportation card, much to his later regret.
Once a young man who was brutally murdered outside a Nightside club, he came back as a zombie to avenge his own death. He is stuck in the Nightside, so in the meantime he does good deeds, often getting in the line of fire because he can't die; but then he can't heal, either, and so he is largely held together by staples and duct tape. He also owns a quite intelligent and armed car from the future.
The Merlin of Arthurian legend is buried underneath Alex's bar, Strangefellows, and sometimes appears in public by possessing Alex Morrisey, an act which Alex finds quite traumatic. Merlin has had his heart ripped out and wants John to find out where it is and get it back to him so he can regain his former strength and glory. Later in the series, it is revealed that it is Taylor himself who is responsible for Merlin losing his heart and death of his lover Nimue. Taylor knows the current whereabouts of Merlin's heart but is keeping it a secret, fearing what would happen to the world if Merlin regained his former power.
Merlin, even without his heart, is so great that during the Angel war he could hold angels both from above and below in check. He is on par or below in power with Lilith if he has his heart.
A collection of faceless assassins that possess anesthetic-filled hypodermic needles for fingers, the Harrowing has been attempting to kill John since he was a child. Unstoppable by normal means and nearly indestructible, Taylor has managed to either avoid them or escape from them when assisted by powerful forces. The Harrowing locate Taylor when he attempts to use his gift, which allows those who can detect his ability to home in on him. It's revealed that the Harrowing are actually Taylor's friends and former allies and clients, sent back in time from one potential future where Taylor is primarily responsible for the death of all life on Earth, with the intent of questioning and executing him.
A man who supposedly made a deal with the Abrahamic God. As long as he walks the path of God no weapon of the earth or men can hurt him. If he loses his faith for even a moment, he will lose his powers and become only a man. He is one of the most powerful major players in the Nightside and is the only being who has come close to killing Razor Eddie.
The series.
Short fiction.
These nine stories, along with the new novella "The Big Game", were collected in "Tales From the Nightside" (Ace January 6, 2015).