The first three hundred pages of this book are pure mystery, which is not generally a genre I seek out, and then the rest is suddenly action-packed fantasy. The mood and pacing shift was rather jarring and could have been edited much better, but that is my most significant complaint about this book. Steele is a former photojournalist and documented more than his fair share of war; after becoming disheartened by it, he moved to Switzerland and wrote this book. His worldview of absolute good and absolute evil permeate the novel, and it's easy to see how that grew out of his prior work.
He's a pretty good writer, as well, though the dialogue was a little stilted. His characters tend to speak in exactly the same way throughout the 500+ pages, using the same turns of phrase and exclamations. People are a little more varied than that, so having Katherine, one of the three protagonists, say "geeze" at least once a page can get a little old. Steele's descriptive work is great, though, and he is at his best when dealing with the character called Marc Rochat.
Regarding the sudden switch from mystery to fantasy: I understand Steele wanting to keep the reader curious, but the first 3/4 of the book is so impenetrable that I nearly gave up on it. SOMETHING is going on, but neither the protagonists nor we have any idea what it may be, beyond its sinister nature. Then all of a sudden - for lack of a better phrase - shit starts hitting the fan like no one's business. All at once, we're told exactly what's happening and who everyone is, and the transition from utter darkness to full bright light is simply too much. Steele needed to leave us better clues earlier in the book so we could reach the conclusion on our own and so he wouldn't have to reveal quite so much all in one go. That, however, is an editor's job, not necessarily the first-time novelist's. Steele has clear talent as a writer, he just needs a little help on structure.