The Deep was something of a blind-buy for me-- I was familiar with Crowley's name, but none of his books or his writing tendencies. A lot of fellow Gene Wolfe fans seem to enjoy his work, so that was reason enough for me to give it a shot. 

The Deep is, more or less, a reimagining of The War of the Roses, centering on warring factions, in this case the 'Reds' and the 'Blacks', in a time and place that's minimally and often disorientingly described. The distinct element here that brings it into the realm of speculative fiction however, is a character simply referred to as "The Visitor" a vaguely artificial, sexless, featureless amnesiac, who crashed from the heavens in an egg-like pod. The Visitor gets to know the people of the world and learns from them... and in the process, learns of itself and why it's here. As the novel comes to a close, the Visitor's purpose becomes more bizarre and ambiguously sinister. 

It's a novel that isn't exactly concerned with worldbuilding in the way that most sci-fi and fantasy novels are. This isn't to say that there's none of it, there's enough detail to give the reader an idea of the world and its culture... but like Wolfe's work, the main driving force is Crowley's clever, enrapturing, sometimes archaic prose, strange genre-bending concepts and thoughtful commentary on the darker side of human nature. It can be a bit difficult to get into at first, with a large cast of characters whose names are derivative of their faction colors (Redhand, Red Senlin, Fauconred, etc), but as a debut novel, it's pretty fantastic and I haven't read anything quite like it.