The White Wolf games usually have a helpful section that describes the themes of the game - ideas to emphasize when you're running it. If we were going to include a section like that what would the themes be?

- Conspiracy: yes, it could just be a lone group of heretics conducting their unholy rituals, but where did they get that bit of Xenos technology?

- Paranoia: you're not the only group of acolytes investigating them. Is the other group another cell working for your Inquisitor? If so, why did he/she assign two? Are they working for someone else? And why are they hiding the truth?

- The Price of Knowledge: Ignorance is a blessing. In order to combat threats to the Imperium you'll need to know them more deeply than members of almost any organization. That knowledge will come with a price.

Note that there is actually a section on themes in the DH corebook, p. 220.

Still, a cool topic. Here's what I came up with so far:

Corruption Within

As the hive spires gleam in the sun, their untended foundations gather rust and mold. The governor wears beautiful, ornate gloves to conceal the festering scabs covering his skin, and his courtesans' gilded smiles are drug-induced, for otherwise they'd visibly tremble at the thought of perversions inflicted upon them each night. In the shadow of the granite statue of Saint Sanguinus, shady people meet for sinister purposes, their whispered conversations drowned out by the litanies blasting incessantly from ubiquitous laud-hailers. The Imperium rots from within, but signs of decay are masked by monumental grandeur and superficial piety. Sometimes, the mask is good enough to lull even those tasked with keeping vigil. Can you spot the real threat before it's too late?

Innocence Proves Nothing : Yes, it's a much abused quote. But it's very true. There are plenty of secrets that the Imperium will kill - has no choice but to kill - to keep. An otherwise blameless individual being in the wrong place at the wrong time and seeing the wrong thing is one of the worst crimes the Imperium can imagine.

When I GM Dark Heresy the following things usually comes up as the core themes.

Duty

Faith

Brotherhood/Sisterhood

Sacrifice

Guilt

Whatever happens: You will not be missed.

Especially not if they get a chance for a second shot.

Especially not if they get a chance for a second shot.

Very funny!

These were all very useful. The "corruption within" one was particularly good for generating seeds - nearly everything that shouldn't have anything to do with heresy might.

Re themes like Sacrifice, Brotherhood, and Faith - how do you "hit" those in your games? Can you give me some examples I can use?

Especially not if they get a chance for a second shot.

Very funny!

These were all very useful. The "corruption within" one was particularly good for generating seeds - nearly everything that shouldn't have anything to do with heresy might.

Re themes like Sacrifice, Brotherhood, and Faith - how do you "hit" those in your games? Can you give me some examples I can use?

I will try although I am often fairly poor at this kind of thing but I will try to give some examples.

Sacrifice - Its all about what you sacrifice and what sacrifices that will be made for the Emperor and the Imperium. Maybe you know that there heretics are planning to murder your family but instead of protecting them you go to save the hive from having a Greater Daemon summoned within it. Maybe you give up some prize possession that you've shed blood, sweat and tears for in order to gain some information about a damnable xenos race from a borderline heretical xenologist. Or maybe even sacrifice yourself to become a Radical and wield the tools of the Chaos against itself, and so spare others from the same fate.

Brotherhood - In most functional cells of Acolytes I've seen so far there develops a kind of sense of brotherhood where you stand up for each other and help each other out, often beyond the call of duty. Given that most groups seems to be geared towards cooperation I would think that this is the most common part. That together with your fellow Acolytes you stand against the darkness with no one but them to aid and shield you. That kind of thing is the nurture of brotherhood.

Faith - I don't really have much information in this but when all hope should be lost and when everything has gone down the fan, faith is there like a shining beacon to gather around.