Dividing a world into mysterious zones is an inspired storytelling concept. The conditions in each zone dictate the type of technology that can be employed, and anyone crossing a zone boundary will suffer from physical distress. It all leads to considerable intrigue and tension as the main characters, Quillon and Meroka, undertake their long journey.
The zonal constraints impart a distinctly steampunk feel, with horses, airships and various steam power contraptions making regular appearances. Each zone tends to have its own collection of inhabitants. Although largely humanoid they often exhibit divergent evolutionary traits, including enigmatic Angels and dark-souled Skullboys. The grotesquely memorable Carnivorgs are an exception.
I found the book both entertaining and easy to read, but it might not appeal to everyone. Some may be unhappy that many certain key aspects are never fully explained. For example the source, number and extent of the zones, or the origins, capabilities and evolutionary map of its humanoid inhabitants. Plot lines are sometimes left hanging in a wait-for-the-sequel type fashion - especially the ending. Yet, as there is no sequel, some readers may feel shortchanged with this approach.
Of course, just as in real life, a fictional book doesn't have to provide all the answers. As a writer, hanging story lines simply stir my imagination. And, in the end, I found this book had a distinctly different feel to other SF books I've read. A good thing in my opinion.