I found WHITE DARKNESS to be an unambitious but fun adventure that makes great use of its historical setting. The atmosphere of WWI-era Haiti enhances the narrative, and makes the background come alive. It adds tension and depth to a story that would otherwise be fairly standard. There were only a handful of passages that didn't work for me, and while it had some relatively significant flaws they weren't quite enough to disrupt the entirety.
The setting is evoked quite effectively; the more historical aspects of the story really shine. McIntee makes good use of the location, so that it, the people, and the culture are vital to the plot. Not all of the individual historical figures seem as three-dimensional as they could be, but the surrounding details more than make up for this. At certain points, I just wanted to soak up the historical facts and ignore the science-fiction story that seemed to be intruding into this nice drama. The book does a great job of balancing the history with the fiction.
A few things pulled WHITE DARKNESS down for me. Some portions of the prose are extremely awkward, and could have been greatly helped by the editor's red pen. There are a few sections that don't really have any impact at all upon anything else, and could probably have been removed. The nature of the enemy was fairly ill-defined, and while this did have certain advantages (it added a bit of mystery and menace) the end result was that it was difficult to feel that this adversary had much strength behind it. Quite a few pieces suffered from the flaw of telling rather than showing, but to the book's credit, I didn't find that particular shortcoming to be overly disruptive in this case.
It's a pity that a scant few problems nearly manage to wreck the rest, as with some mindful editing this could easily have been a much stronger novel. As it is now, it's still quite entertaining, and I'd recommend it for the setting and the atmosphere alone. The plot is straightforward, but not simplistic, and works well in its action/adventure dressing. An enjoyable way of spending a few hours.