Every once in a while you get just a bit of validation for plowing through the genre section at the local bookstore. While reading genre fiction to me is a lot like watching TV, every once in a while you find a diamond in the rough.
Simon Spurrier's book is that for me.
In the 40K universe, where everything is grim and dark, Zso Sahaal of the Night Lords Traitor Space Marine legion crashlands and has something very important and very dear stolen from him. And thus he goes on his quest to recover the object.
Equally, Mita Ashyn is a psyker in the employ of the ruthless Inquisition, there on the same planet to root out possible alien influences. Despite her competency, she is belittled for her skills by her inqusitor and marginalized by the group.
What follows is a story in which, by the end you won't be sure who the real bad guys are. And that's the best thing about it.
Along the way we learn revelations about the character and motives of the Night Haunter, Konrad Curze, why he selected Zso as his successor, and the fate of the Night Lords Legion in the 10,000 year interim between the assassination of the Night Haunter and the release of Zso from his imprisonment.
One brief comment about the story: I think there's a bit of an anti-religion philosophy in the background of the book. Mita for example, had dedicated her life to the Emperor, trusting in his love for her salvation, and thanking him for the psychic gifts she has. By the end of the book she rejects the Emperor and realizes her psychic powers were hers and hers alone all along. If this isn't a nice stab for humanism, I'm not sure what is...
Overall this ranks as one of the best 40K books I've read yet, and for anyone that is "40K curious" I strongly reccommend it.