Charles McLean’s novel The Watcher is one of the best novels I’ve read in a long time, and is well worth a look if you’re in the mood for something weird, gruesome and compelling. It’s the story of an everyday schmoe who commits a random act of horrific violence with no apparant motivation and his subsequent attempts to understand why he did it.
What’s impressive about The Watcher is that it maintains a wholly amiguous stance throughout. While most writers would opt for a definitive conclusion, Maclean maintains several equally convincing realities at once. The book is, I believe, currently out of print, but can be picked up dirt cheap on Amazon.co.uk.