So I just recently finished Henry Zou's second Bastion Wars Novel: Flesh and Iron. I will say I wish I remembered what Emperor's Mercy was about so I could get a little more context into the overall Bastion Wars BUT I will add that is not at all neccessary to have read the first Bastion Wars novel to read this one. And I know I will remember this one, which may be more indicative of quality. Then again, the first one is about an Inquisitor (I am pretty sure) which is pretty generic in terms of 40k novels. However, this one is, I dare say, far more unique than most 40k novels out there, and well worth a read IMO.
For one, I enjoyed the uniqueness of the Imperial Guard regiment: The 31st Riverine. I had actually had an idea like this in my mind for sometime, being from an area where airboats and such are common. Think of this regiment as an equivalent to the Vietnam war river patrols, except entirely crewed by men from Alabama and Louisiana (their planet is even Ouisiva. My spelling may be a little off, but obviously drawn from Louisiana). These men are swamp men, and fight swamp orks on their homeworld (the ideal enemy is any for a swamp regiment). This concept of Cajun Guard is pretty cool and unique.
Another unique Imperial Invention is the great Argo Nauticals- large battleship/aircraft carrier hybrids as far as I could tell. Being in the Navy myself, I found this COOL.
I also highly enjoyed how he switched between the Riverine and the Rebel/Renegade perspective thoughout the book. Mr. Zou does a really good job of getting the reader to empathize with Chaos, rather than just see it as evil. In addition, he does one thing I always appreciate- gets the reader to wholly HATE the ecclesiarchy. I may be an Imperial fan in the 40k universe, but those guys ALWAYS piss me off.
As well, there is a really good twist at about the 3/4 mark that follows through well to the end, rather than the book just ending on the "Conquer the Castle" moment as many BL books are oft to do.
The book is very Heart of Darkness/Apocalypse Now in nature and imagery. Very good writing style and story tempo. I honestly cannot find any flaw in the book and look forward to the next Bastion Wars novel (and will more than likely re-read the first when I get a chance).
All in all, 5 out of 5 aquillas!