The Grey Knights are an interesting chapter and one I know little about (aside from their having AWESOME looking minis) so I decided to pick this up and read it. After all, everything you want to know about the GK's in one big book, rock. I don't know the reps of most WH40K authors and usually I don't care. Most fan bases tend to polarize when it come to authors ranking some as gods and some as hacks often for the smallest flub in a story. Occasionally it's warranted, sometimes not. Apparently Ben Counter, the author of all three of these books, has a reputation as a hack in WH40K.
The first book, Grey Knights, is a solid story overall. Plotting worthy of a greater daemon of Tzeentch, the Imperium portrayed as the harsh and truly brutal place it is, tons of information on the GKs, and the Inquisition portrayed fairly reasonably. On the whole it was a solid and very enjoyable read.
The second book, Dark Adeptus, seemed to be going the same direction. The first 3/4s of the book were up to par with the standard set in Grey Knights and it looked to be doing well. The last 1/4 was... I have no idea. I get the distinct impression Counter ran out of ideas and just needed desperately to end the book in any way possible. He'd written up events that could drastically shift the balance of power in the 13th Black Crusade and had to protect the status quo. There are moments of awesome in it but the last 80 pages of the book brings on one WTF? after another. Details below.
2) Thalassa - I knew when she disappeared she'd be important to the story later on. Not really. Yeah she pops back up but so what? Yes, I liked that the same daemon who'd infected Antigonus' body was in her but some kind of build up would have been much better. As is she just appears and gets killed along with the data daemon. It might have been good to have her with the party all along slowly succumbing to the daemon and at the moat have it finally control her or something similar. As is, meh.
3) The AM captain, mistress pile of cogitators. Her reasoning for blowing herself up and what it meant to the story, nothing, just dropped.
4) The AM Tech Guard. I was always waiting for them to be something besides warm bodies in the story. I finished the book and I'm still waiting.
5) Uthranok's behavior period. Why didn't he let the daemonship put a few broadsides into the AM ship and be done with it? Why just leave in a huff after the Castigator melted down? He left the AM ship in orbit and unmolested he just cried his way back to the warp. Why melt the Titan factory down at the end? Even with the loss of the Castigator the presenting of a few hundred titans to Abaddon wouldn't be an insignificant gift. I think this is a case of Counter realizing he needed the AM ship to survive (Nyxos and getting the GKs and Hawkespur off the planet) and the titans needed to be vaped to not muck up the established 13th Black Crusade.
6) Hawkespur - I kept waiting for her to do something besides be sick. Still waiting.
7) The Castigator - Oh sweet Omnissah the Castigator. Everything right up until the end of its heart to heart with Alaric was great. I loved the description of the titan, the portrayal of the actual STC as a self aware program (lets face it, if the STC really was supposed to enable anyone to build anything its going to have to be a pretty damn brilliant program and have a hell of a lot more information than just a set of blueprints), even how it had become twisted over the millenia. Hell it even making a pact with Chaos was interesting. The moment it turned into a daemon though, that was the game. It sucked so hard. I think Counter had the same problem Alaric did, how do you kill something that's just data? Umm... you make it a daemon so the resident GK can kill it. ( "You're a daemon!" "Oh wow, guess the definition fits," *Morph into a physical daemon*. ) Honestly? I think Alaric's explanation was so incredibly weak, it forgot it was a daemon? Really? Even after working with daemons for a thousand years it never realized it was one? The STC was possess and somehow the daemon who did it forgot it was a daemon? Of course the alternate is just as bad, that if don't think yourself bad you don't get physically corrupted, something that is just wrong in WH40K. I think this is a solid case of Counter realizing just what he'd created after he did it. Something that can control and work with Chaos but cannot be corrupted. Something that would be a quantum shift in WH40K, so he had to bring it back down to out level. Then there's the way the titan itself died. A couple melta bombs down an access tube to the knee and it's reactor vapes....oookkkkk...
8) I will say this, Scareos' army at the end was good as was Antigonus' in the final battle. Very good stuff there.
I haven't gotten into Hammer of Daemons yet and after the way Dark Adeptus ended I don't know if I want to.