The Imperial Guard including the Chiliade 52 is stuck in a pacification on Nurth campaign that uses the Chaos powers to resist. The Alpha Legion came to the rescue, a young but twisted legion, using espionage and other tactics including barbouzardes in custody. But who actually called the Alpha Legion? The Cabal, a group XĂ©nos even older than humanity, having also spies, capable of mounting plans for decades and whose ultimate goal is annihilation of the primordial annihilator (Chaos).
The action takes place shortly before the Horus Heresy and you will discover why and rallying the Alpha Legion chaos. For the first time in the series, they are not the Marines who are central to the novel, but the Imperial Guard (Abnett like men (see the ghosts of Gaunt) and me too).
The structure of the Chiliade is very interesting, though, as usual, Abnett plunges us into his world, directly into the deep end without armbands, and we must admit we train (almost even poured) the first 50 pages.
Some characters like John Grammaticus, spy Cabal, are treated, but others would have deserved a more comprehensive development, particularly within the Chiliade.
You must love the style of the universe Abnett Wh 40k, often a little dry, not short on details but sometimes rough and connoisseurs. On the other hand, get to Volume 7 of the series enables to form a small Warhammerienne culture not?