Neil Gaiman's Neverwhere is set in London - both London Above and London Below. Wait - you thought London was London? Then clearly you are a member of London Above.
The inhabitants of London Below are nearly invisible to their Above counterparts. Richard, a twentyish Scot businessman, is on his way to an important dinner with his fiancee when she merely steps over the bleeding body of a young girl, Door. When Richard stops to help her, his fiancee doesn't understand why he is bothering. It's as if somehow only Richard can fully see Door. This encounter leads to Richard fading from the view of people in his life.
When his apartment is being rented out from beneath his feet, his office belongings packed up and stored somewhere, Richard decides to do what he can and reclaim his life. London Below is revealed.
This is your typical quest book. Door wants to find out who's responsible for the murder of her parents. Hunter is after the next big kill. Richard wants to get back to his normal, safe, boring London Above life. Will they find what they're looking for?
The descriptions are incredibly vivid - from the ghostly Metro to to nightmare Night's Bridge. It makes sense that this book is actually the novelization of a BBC miniseries. London Below is often dark, dank, dirty, foggy - but then again, as Door points out, so is London above. In fact, I learned a bit about killer fog from reading Neverwhere. See? Books make you smarter!
Overall, I did really enjoy the book. I'm sorry it took me so long to read one of Gaiman's full length works. My only other experience had been with one of his short stories. As I was reading, I kept wishing I've visited London so as to get more of the references, but it's certainly not necessary to appreciate the book. This is a perfect October read, so if you haven't read it yet, go get yourself a copy!