Emma Bannon is a powerful sorceress in service to the British Empire. When the mutilated corpses of mentaths (super-geniuses) start showing up, she is the only one to link the deaths to a potential threat to Britain itself. She manages to save the last mentath from an assassination attempt, then enlists him to her cause. While Emma investigates the sorcerous conspiracy, Archibald Clare the mentath pounds the pavement looking for clues.
Archibald Clare is the weakest part of this book. He's supposedly this fantasy/steampunk world's version of Sherlock Holmes, but he talks in a bad knock-off of a dithering public school accent: lots of "I say!" and "Good day sir" and "how improper". (I'm not exagerating in the least--these are actual samples of actual dialog.) He's a genius, but I saw no examples within the text. For instance, Emma mentions that she was a poor orphan, and three pages later he "deduces" that she grew up poor based on her table manners. She just told you, dimwit! Alas, it seems that he is a permanent main character.
Emma's sections of the book are just as silly as Archibald's but at least she does
things. Her magic is dramatic and dark. The dragons she encounters are easily the most interesting aspects of the book, being both intriguing twists on the usual bodies dragons get and
sounding quite frightening. And I loved that she was a balls-to-the-wall kind of badass, who throws her all into a battle and then, having barely survived, immediately fight another. She has a series of furious rides that are downright inspiring. Fans of Anne Bishop's Black Jewels series will like her; I certainly did. She's like a normal dark sorceress cranked up to 11.
The plot is basically just a bunch of random ideas Saintcrow throws at the heroes, without much development or explanation. So don't read this if you're expecting a mystery, because there aren't clues or hidden threads or anything like. But do read this if you're in the mood for flashy clockwork creatures and campy pseudo-Victorian dialog.