This is apparently a science fiction book. I mean, it must be, it's been nominated for the Nebula and all! And it's published by Tor! Of course it's sci-fi! Well, no, it's not. While it does use the common sci-fi trope of being set in an alternate history (and a rather pedestrian one at that - peace between Britain and Germany in 1941) the story itself is just a country-house detective mystery, with political meddling. A fairly competently executed one too. While it's obvious from the start whodunnit (or at least oneofwhodunnit) the whydunnit isn't clear at first, and it's fun to see the investigation flail around a bit. On the other hand, the characters are a bit two-dimensional and stereotyped. Stupid aristocrats. Nasty aristocrats. Good copper with a hidden past. Nasty Nazis. And the Jewish hero is, of course, a banker. In summary, worth reading, but wait for the paperback. The book is apparently the first in a trilogy, I'll give the second installment a try.