Angron's Monolith by Steve Lyons
The book is set during the Third War for Armageddon where the Relictors have deployed themselves in the equatorial jungle under the guise of cleansing the denizen Feral Orks who have taken up residence there. In reality they are pursuing their own secret mission to recover Angron's Monolith. If you don't know much about the Relictors and their super-secret pastime, then it's probably best to get some background on them first.
The book starts with the marines sweeping the jungle killing off groups of Orks as they find them. This is how we are introduced to the two main characters of the book; Tarryn and Baeloch. As the story develops these two marines become caught up in progressively more bizarre events as the secrets of their Space Marine Chapter are unintentionally revealed to them. Eventually we reach a point (not surprisingly about the time they find the Monolith) where they must choose to remain loyal to their Chapter and embrace it's less than wholesome secrets, or turn their back on their brothers and remain loyal to the leader of humanity; the Emperor of mankind.
I found the story interesting in that it helped bring some more colour and detail to a commonly known piece of Relictors history that has not really been explored. However, I was saddened by some of the narrative towards the end of the book as it seemed all a bit too cliché. There was an opportunity to grow and embellish the interesting history of this space marine legion and I believe it was squandered.
All in all, this novella would be interesting to those of us who have a love for this particular Space Marine Legion, but those who don't wouldn't miss much by not reading it.
If the grass is greener on the other side, you can bet the water bill is higher...