Good to be back in the Heresy timeline again (Descent of Angels doesn't count, for reasons made apperent in my review); although this is another side show piece dealing with the initial moves by the Word Bearers against the Ultramarines.
The action is good, gripping and almost without pause throughout the book, there is a good range of characters within a small group of Marines, drawn from several legions, that make for surprising and interesting allies.
Counter is still learning his craft as a writer and there are moments in this book where it shows, I lost count of the amount of times someone in close combat 'used his momentum' to do something; I know that’s how it’s done but some more imagination would be nice. And descriptions of craft 'Thunking' down on decks along with other strange noise descriptions grated a little.
There are some very obvious nods from iconic films within the books dialogue, I spotted both Predator and Lord of the Rings; but these weren't unwelcome and never strayed towards the realms of plagiarism.
Also the writer seems to suffer from the same affliction of most of the Black Libraries staff, they can't keep track of numbers; killing off limited amounts of Marines with careless abandon (so much for being super soldiers who know no fear) but just when you think they should all be dead there seems to be another bunch waiting in the wings to be incinerated or eviscerated or vaporised and so on.
That said I did enjoy this book and despite it being surplus to requirments with regards the main thread of the series, it’s a steady and welcome return to form.