This came out last week, the latest book for Dark Heresy (it's still dark). It's the perhaps long awaited guide to the Borg, I mean the Mechanicus. Specifically it's the guide to the Calixian iteration of the cult. This is not a history of Mars, nor is it a broad sourcebook. But then none of the sourcebooks have been. Fortunately 40k is such that you don't really need books on Terra, Mars, or such locations. Though given that apparently a giant Necron thing lives beneath Mars it might be interesting to know. But that's the deal with FFG: you use their sandbox or steal the ideas they created for your own locale. Fortunately FFG has done well in that aspect, if not the rules.

Fortunately also, though I haven't read it all, FFG seems to have started getting it's act together. This book doesn't appear to be full of mistakes, though I can't speak for the rules (and some people are already saying that one of the character options, the Crimson Guard, are overpowered).

Maybe it's the scent of machine unguents or the polluted haze that surrounds their Forge Worlds, but this is actually one of the better books. It's quite thin (about the same size as all the rest) and also has an adventure. But the ideas presented are quite good. This isn't the last word on all things Mechanicus and it doesn't give much info regarding technology; the arsenal that's there is quite short. There are no rules for vehicles (still) nor voidshops (still) specifically oriented to DH (presumaby one is meant to lug around the RT books that cover this stuff as well, which is pretty fucking heavy if you're also carrying thy DH books also).

The book starts with a very broad history of the cult followed by a narrower focus on the local cult history which is presented in a concise and not painful to read fashion. Some fun tech heresy (one guy going around in his spaceship with his followers unleashing viruses on planets and bombing others into the c'taan age). In general the Mechanicus is quite isolationist within Calixis and is dominated by the Lords Dragon, it's secret police, that got its claws into the Lathe system during the Angevin Crusade and genetically engineered most of the population it found to work for it. NOwadays the Lords Dragon spy on the rest of the sector from their dreaded Panopticon station. There is an 'Iron Wall of Silence' (not sure why it needs to be capitalised but the book is quite jargon and faux latin heavy) that has existed for many centuries that serves to bar the likes of teh Inquisition from nosing around Mechanicus territory and affairs. In general the Mechanicus is not intrinsically corrupt though tech heresy seems to be quite prevalent in the sector (natch). They just don't want the rest of society on their land.

Character options include an agent of the aforementioned Lords Dragon, a Lathemaster (a genetically engineered factory worker that's quite hardy and tough), a Factor (an ambassador of sorts for the cult, able to interact more with regular human society), a mech assassin, and a member of the Cult of the Pure Form. This option is interesting though perhaps not to play as they are not a part of mechanicus society given that they don't like cybernetics and want technology under pure human control, as the God Emperor of course would have wanted. Essentially anyone with cybernetics has to have them removed upon joining. There is also a Calixian Malatek which i'm sure was in the Radical Book, but I have to check (I haven't, sue me). In this context they have the ability to learn an affinity for a particularly almost-heretical line of research (the void, archaeotech and xenostech iirc). Malateks are sort of outcasts, but, curiously, are not actually hereteks. They are one step removed. Consequently Inqusitors might enjoy their service. Finally the Crimson Guard is a replacement Guardsman option for Calixian Skitarii (well almost, the book doesn't give stats for playing a Skitarii by name oddly). These are the local cult soldiers and they are meant to be fuck hard.

There are a couple of Elite Career advantages: one is a Cistron, which is a particular agent of hte LOrds Dragon, and a sort of technological 'void' called a Discordant. Cistrons are sleeper agents with an altered personality that is resurfacing. They are supposed to have a handler but something went wrong... Discordants are pretty much as described, though their ability (with a roll of commensurate difficulty they can fuck with tech) and are anathema to the cult. Both are decent enough ideas, but that's all she wrote.

The gear section is, as said, brief, but includes some new weapon qualities including Integrated WEapons that run off a Mechanicusist's potential coil.

The next section is all about the Lathe Worlds proper which I imagine is quite interesting but I haven't read it so fuck off. Go away.

Sounds good, thanks for the write-up.

Given the Necron revamp recently, I wonder if the Void Dragon is still canonically underneath Mars? While I think it's a very interesting plot hook, I also think it's too high-level for the RPG's to be dealing with. That, becoming open knowledge, is the sort of secret that could tear the Imperium apart.

It's on a par with the idea of the Golden Throne failing. It will probably never be realised and is just speculation. That is unless it can be used to sell more Space Marines.

The book is filled with lots of wierd phrases, mainly latin terms for various ranks. This gets a bit overwhelming at times. Some of it is pure fluff and is quite evocative, but there is a lot of it.

So as Only War will round out the setting (i believe it's set in part of the Calixis) that rounds out the setting in terms of the official Imperium components, as far as i can tell.

The only issue with the Lathe Worlds setting is that, according to the book, the strange gravity strresses of the region make it difficult for outsiders to exist wihtin (not sure how that works in reverse). It says they need support mechanisms. Even then, it is sovereign territory. So all this good stuff may well remain untapped.

There is a web supplement for this book.

I suppose it's better than not releasing it at all. But given how important the material it contains is (trumping even the need for an adventure, regardless of whatever the quality of the included one is) I am once again staggered at the stupidity shown by the editing staff. This web addon is about 13 pages long and could very easily have been part of the main book!

I think FFG are beyond even the grace of the Omnissiah at this point, now i have to get this stuff printed which will cost a bloody fortune if I can find a library still open.

Work printers are your friend.  Just a helpful hint.

Surely the real issue, other than assuming i have access to free printing (I don't), is that excising material that's essential to the concept behind and the function of a supplement in favour of an adventure is a piss poor editorial decision. This is what's wrong with FFG. Regardless of how excellent the adventure might be, or how bogus the web supplement (it contains character creation stuff for pc's originating in the Lathe Worlds), there are certain objectives behind a book. If those are ignored then something has gone wrong.

I have now finished the book bar the adventure which appears to be a straight up Mechanicus facility dabbling in Warp research affair. I'll read that later, the quality or plot isn't really relevant IMO. What's more important is why it's inclusion trumps the mechanical information that was excised from the final cut. FFG's line managers are the root of their problems. They have no idea about rpg book design, puitting across information, or what is important.

Anyway, the remaining material is a discussion of the Lathe Worlds themselves which includes territory beyond the LAthe Worlds proper and all Mechanicus territory in the sector. Or at least a sampling thereof. So we get a discussion on the three Lathe Worlds proper most of which seem to be in some sort of turmoil with schemes and plots agogo. One of them doesn't seem to be making much anymore either.
Then there's discussion of some of the other worlds and places within the system including an artificial planet (or is it?) the stores all manner of forbidden stuff under heavy guard, and a planet that's used as a giant weapon's testing facility.
The rest are facilities outside of the actual LAthe's system which itself, inexplicably, has two separate names. In the past (ie the time Calixis was conquered) it was called Pondus Impare, then it's called the Sentanim system, because that's the name of the star. I don't get this. Mostly it's just called the Lathes.
These facilities include: a world shrouded in darkness due to atmospheric detritus and essentially hidden. It's called Lacuna. Some of the science in this book is pure guff (and i'm talking relatively). But that's ok. It's generally off limits unless you can convince the Magos that runs the place.
There's a station on a feudal world that's slowly upgrading the tech level of the surrounding population it uses to produce food for other worlds. So it's all very Tech Knights and Servitor Stallions.
There's a Titan facility that has a vast penal facility whose inhabitants are target practice. No stats for titans, just the titan pilots. I'm not sure why they are included quite honestly.
There's a secret Mechanicus interrogation facility that tortures hereteks (and possibly psykers) and stores their secrets.
And there's a spaceship that flies around broadcasting hymns to the Machine God that has the effect of raising faith in him. Built by a formerly outcast Magos some question whether he's genuinely rallying the faithful, or building his own powerbase.