Told from the perspective of a rather stick-in-the-mud assistant investigator to a genius detective who has been banished to the hinterlands for unspecified faux pas against powerful people of the Empire, we follow as their investigation goes from strange to dangerous as it threatens powerful people and the very walls the Empire is founded on.

The primary conceit for the universe he creates this time is that genetic alterations are but a flask of chemicals away and the whole Empire is largely run by various highly modified individuals. The narrator has just been given his first modification, making him an engraver, which means he has perfect memory of anything he views or hears or smells. He is the eyes and ears for the investigator, relaying the physical clues to her from which she deduces the rest.

Strongly recommended read! Really well plotted, great characters and a fascinating world for them to run around and get in trouble in.