If you are unfamiliar with the taint of chaos or haven't been privy to the exploits of the superhuman Space Marines then you probably might want to give this book a skip. But if on the other hand you are someone who is familiar with the Warhammer 40K Universe and are curious to know more about its History and how things came to be then this is a must read. The story is seen unfolding from the eyes of Garviel Loken, Captain of the Luna Wolves 10th Company. The Emperor has returned back to Terra and delegated the responsibility of carrying on the Great Crusade to his favored son Horus Lupercal who has now been elevated to the newly created title of Warmaster thus giving him command of all Imperial Military forces. The decree of the emperor and its interpretations give rise to tensions and this is what forms the main theme of the book and I believe will carry forward in the series. As a standalone read this book (though a slick read with great characters) may not offer much but it definitely gives the reader a view into the minds of the Astartes as they grapple with the interpretation of the Emperors will and their own beliefs. Definitely a must read for the Warhammer 40K Fan!