How abstract are you willing to go? If you're not scared of a little meta then this book is for you. This book takes an LSD trip and combines it with an ever lasting Virtual reality trip. Drugs are administered through feathers, which you almost swallow. That's pretty much the most concrete one can get describing the contents of this novel.
The plot revolves around a writer (Scribble) who loses his sister in an out of control virtual reality drug trip. In exchange he ends up with a being from that reality. In the rest of the book the main character tries to rescue his sister by trading back the alien for his sister. Reading this feels like being chased by sensory overload, as if that could be a monster hunting you.
Vurt is often compared to works by William Gibson, but unlike Gibson Jeff Noon actually provides assistance here and there to help you understand the maddening world of the protagonist. It takes effort reading this novel but it's worth it. Once you get used to the language, the character confusions and the reality stretching world descriptions, you're in for quite a trip.
If you can get a hold of a library edition then try that first, although the book is good, it's definitely an acquired taste.