Bitter Seeds begins with an ominous scene in Germany in 1920. A trio of orphans are dropped of at an orphanage that pays money for healthy children. Only two of them manage to get in the door. After a pair of brief glimpses of the two other major characters as children, Tregillis takes us swiftly to the end of the Spanish Civil War and it becomes clear that this is no ordinary war story when a defector and potential informant spontaneously combusts in a hotel bar.
The Germans have been up to something. There have been stories and even History Channel specials about the Nazis interest in the occult and the arcane. Tregillis takes this historical fact and runs with it. The doctor from the prologue has been experimenting on children, to try and turn them into Uebermenschen and apparently, he's succeeded. Not only that, but the teenagers those experiments turned into are a vital part of the Nazi war machine.
After Dunkirk, the history starts to derail because one of those teenagers can see the future. Gretel is one of the more terrifying characters in this book. In a Big Idea piece he wrote for John Scalzi's blog, Tregillis writes that he was inspired by the question "I started to wonder… What if, instead of thinking 30 seconds ahead, the precog had been thinking 30 YEARS ahead? And hey, while we’re at it, what if she were a sociopath, too? (You know, just for fun.)" As a reader, you never know what Gretel is going to do. Once Tregillis took History off its track, it's impossible to predict what's going to happen, especially once the Red Army shows up early.
With a precognitive, a fire starter, a telekinetic, and others, it started to feel like the Brits were helpless during the Battle of Britain. But the other two children, all grown up and working for the Admiralty, have (sort of) a plan to strike back. Marsh, a hero with violent tendencies when his family is threatened, asks his friend Will, the younger son of a duke, to use the things that his grandfather taught him to defend the realm. On the book jacket and in the reviews, Will and his mates are described as warlocks, but that's not quite accurate. What they do is make deals with Cthuloid creatures that really, really don't like humans. And the only coin they accept is blood and death. Any victory the Brits have quickly becomes a Pyrrhic one.
So, as Eddie Izzard would say, yeah. It's a lot to digest. But it's one of the most imaginative books I've encountered in a while. At least since the last Brandon Sanderson book came out (not the one he co-wrote with the late Robert Jordan, but the one before that). Bitter Seeds is masterfully written. Tense from the first chapter to the last. Unpredictable. And Tregillis treads the fine line between revealing too much and revealing just enough for the reader to understand--which after hanging around for the last season of Lost I really appreciate. This is a great book and it deserves to win some awards when science fiction award season rolls around again.