I will try and keep it spoiler free!
Before I start I know that on writing this I am starting to drift into Aaron Dembski-Bowden (ABD) fan boy territory but his recent writings have been that good I'm willing to accept it. Soul Hunter was good, First Heretic was better and Blood Reaver doesn't fail to deliver.
ADB again picks up the tale of Talos Prophet of the Night Lords legion or what is left of it as they continue to pursue a victory in a war that many have now given up on. The book sees them take the fight to the Imperium looking for that oh so important commodity gene seed however hard times have befallen the once proud eighth legion and they seek assistance from the Blood Reaver himself, the Tyrant of Badab. This leads them getting caught up in one of his schemes and plots against the Imperium. There is also an interesting side plaot involving Talos' slaves and general life aboard the ship which shows another side to the seedy under belly of the 40k universe. Other than that I don't want to go into the story any more, you can read it instead I'll tell you what I loved about it.
What ADB does better than anyone I think is he gives you an inner turmoil as a reader as to who you are meant to be rooting for. Regular readers will know that I am a pure Imperium player, good guys for the win but what ADB shows you and this is a key feature of Grim Dark, is that there are no good guys. Talos as I see it is as 'good' a character as you get in 40K, he fights for his Primarch, he believes that (some) evil should be punished and he protects the people who serve him and his chapter but he has the harsh reality of a setting that is imperfect. Talos constantly harks back to a simpler time when all of his brothers served as he did under their perfect father while his brothers treat this memory with scorn because they know that this never existed.
ADB manages to give a sense of realism to his characters and this brings me back to what he said to me last year when he questioned my review of Prospero Burns. He certainly creates a less characturesque (is that even a real word?) view of the 40K universe. What drives the characters is far more real rather than just 'DEATH TO THE EMPEROR' or 'DEATH TO THE ENEMIES OF THE EMPEROR'. His characters love and desire and this does add in a grown up factor to the story.
As with all his books there wasn't a lot that I didn't like bar the last battle scene which was perhaps a little quick. I also would have liked a bit more Huron but again you can't have everything in life. My other major gripe is the hints at what the next book will be about, is it too much of a give away to point to Eldar seeing as they are mentioned so often? Come on, I hate spoilers when you know that the next one is so far away.
Over the last year ADB has firmly become my favourite Black Library author even if Battle for the Fang has overtaken First Heretic as my favourite book. Hope you enjoy reading this one as much as I did when it finally comes out in shops.