Konnici na Liriite - Chevalier Du Lys

Undoubtedly a great book. Undoubtedly if you are Warhammer 40k fan. If you are new to the world then you will probably not enjoy it. It’s about about the nature of the Inquisition. Inquisitors and their search for knowledge. To know thy enemy but doing so violating rules of the inquisition. You'll get detailed information with every alien autopsy. It's a short amount dedicated to each race but almost every one are portraided there.
Now the story behind the sourcebook... the premise of the book is that it is a report based on the lab contents and notes of a "heretical" Imperial inquisitor. The report was supposedly made by an inquisitor sent to shut down the lab and document the contents before destroying them. The contents of each page are designed to look like notes made in haste about each specimen and document found in the lab. This includes notes on alien physiology and behavior with anatomical diagrams and more. Not only the Orks, Tau, Eldar and Tyranids are shown there but also the almost incognito Umbra, the old Hrud and several others... most importantly, connections are drawn between each case study that point to the role the Slaan and C'tan play in the fate of all the races of the galaxy, as first suggested in Codex: Necrons.
The art in the book is not the best from Black Library but the story compensates it. This is how a inquisitorial analysis look like. In there it has eyewitness reports of each species, dissection notes (with diagrams and all), several heretical texts.
The mystery starts to unfold as we progress through the book. This book it's a murder mystery in the world of 40k. I think that's almost unique in all books published by GW or Black Library and that's why that this book it's loved. And it was written by Simon Spurrier who has written Lord of the Night (The only book with the NightLords) and Fire Warrior (With the viewpoint of the Tau.)