While the Spook and his apprentice were busy fighting the dark supernatural things
their country was fighting a big war nobody cared much about (World War I would be a good analogy). Still a war is a war and quiet almost backward part of the world where Spook
lived finally saw military action. It is overrun by raider parties and is about to be conquered. Spook's biggest treasure and his main goal in life - his library - is destroyed and he and Tom had to run to a remote island. To make matters worse an old enemy of both Spook and his apprentice is on the loose and she is royally pissed off at both of them.
This was the first time of my read of the series when I was really tempted to give this one the highest rating. I thought I knew what would happen from the beginning of the story, but the plot twist in the middle completely ruined my prediction. The action was good and the world was very much alive and dark. The usual theme of acceptability of using evil means (or plain cooperation with evil) to fight evil is further developed in some interesting situations. Unfortunately by the end the book kind of dragged and the ending was somewhat abrupt.
I also became a little overfed on the fact that the good guys really come up on a losing side globally speaking despite their local victories earned with great sacrifices. Some breaks for them now and then would be really nice; see Harry Dresden for another example of this. I also have a strong suspicion some of the main characters of the series will not survive the next book.
The writing quality and the plot were good enough for solid 4 stars, so this would be its rating. I look forward to reading the next installment of the series.