Image Copyright Games Workshop, used without permission.
Out of all the Black Library books I've read, it's the first I've really felt "compelled" to spread the word about, so that should tell you something.
Full Disclosure: My main army is Space Wolves. So I'm a bit biased towards the furry dudes.
If you have been living in a closet, you may not have heard of the Horus Heresy books.These books are set in the early days of the Imperium, usually just after the Emperor turned over control of the crusade to Horus and tell the story of Horus' betrayal of the Emperor (Wait, should I have given a spoiler alert for that part? Sorry guys, Horus turns out to be a bad guy. ;)
The story of Prospoero Burns follows the adventures of a historian/archivist who goes to study and live with the Space Wolves chapter of the Emperor's finest. The Space Wolves have a reputation of being among the most savage and feral of all the Space Marines, and in this book you get to peek "behind the curtain" a bit as to the origins of their feral nature.
I believe that Abnett really outdid himself with this book. It takes the Space Wolves in a different direction than they have often been portrayed in the past. These guys are not walking around with mohawks, that's for sure, and they aren't "space dwarves," goofy and drunk all the time.
These Space Wolves are more akin to the Wolves that exist in MY mind, the ones that I paint and play - with a grittier and more serious tone. Abnett shows that the apparent recklessness of the Wolves is really just a psychological tool - that in reality they are among the most disciplined warriors of the Imperium who use fear as a weapon and never hold back from even the grimmest tasks given to them by the Emperor. They use any tactic and any weapon, and pursue victory at all costs. (But somehow if I use six Razorbacks and fifteen Longfangs to win I'm not being "fluffy...?").
The story itself is head and shoulders above a lot of the "brain candy" that you get from "popular" sci-fi novels. I felt that I was reading a good psychological thriller/horror at times, with scenes that leave you guessing about where reality starts and imagination ends. Of course, with Tzeentch in the picture, is there any difference really?
Anyways, the book is great, I highly recommend it whether you are into Space Wolves or not. If you didn't like them in the past, you might find yourself enjoying this new, updated image (which is ironic because it's describing them thousands of years before "present" 40k).
Oh, and there's a line from the book where they are talking about the philosophy of Leman Russ that totally justifies my 13th company army's using Chaos Steeds. Those of you who read it can probably figure it out.