This book is creepy. It's a story about magic being used for war, and so in that sense it shares something with Jonathan Strange and Mr Norrell, but during World War II, and against the Nazis. And instead of negotiating terms with the intuitive Earth and with the wacky crazy Fairies, negotiation is done in terms of blood with beings that are all the more disturbing by being entirely sane and rational goal-seeking entities.

On the English side, there's Will and Marsh. On the German side, there's Klaus and Gretel. The Engishmen are clearly the good guys and the Germans are the monsters... or so it seems at the beginning, until it becomes apparent that all of them will kill for their own reasons. Klaus in particular is sympathetic to people that he really shouldn't be, while Gretel's odd precog behavior may be an indication that she is mad and enjoys death and destruction, or that she is trying to save her friends from an unseen cloud of world-ending futures.

The book does not have any kind of a conclusion, and so is clearly planned as a sequence of two. There are hints about plot points in the next two books, notably the reason for the Eidolon's hatred of humanity being because of humanity's own "violition" being exercised through the batteries. There are elements of the Anubis Gates in the story, through the workings of fate to the odd primacy of Marsh's character, but this is a bleak tale that talks about the entirely mechanistic and reasonable way that the unthinkable becomes commonplace to a war machine, even at the cost of sanity itself.