Here's one idea for your cult and plot, lifted partially from my aborted Deathwatch campaign (mine was a much more xenos slant to it, but malleus feels better if you want focus on a cult).

Intelligence reports of lowered harvest output, combined with mysterious deaths lead to the acolytes being sent to the planet to investigate. Covertly inserted into one of the scummier sections of a city, they have only basic equipment and survival gear on them and have to buy, steal or commandeer anything else they may need, with varying repurcussions. During the investigations clues are found that hint at a shadowy group or cult behind the planets issues.

This allows you to set the scene, characters and mood of the adventure/campaign and, pardon the pun, throws the PCs in at the deep end, with only their wits and their skills to back them up. If after enough investigation or just plain GM clue-dropping they discover enough about the cult to proceed, you then kick up the tempo and have cult start fighting back. Set on a water world, you can throw fish-men mutants at the PCs as interference, plus dangerous sea creatures unleashed by the cult.

When the PCs finally get to fighting the real core of the cult, reveal to them that the cult is actually not all that well directed, seemingly being controlled by some shadowy entity hidden away in the depths of the oceans. A cult centred around octopi would give you the room to have a figuredhead for the cult, or 'Maw', with 8 officers or assistants, the 'Tentacles', and then hordes of mutants and muscle. As such a good name would be Cult Of The Maw If you are wanting the cult to be of malleus origin, i would personally go Nurgle and have the cult tampering with the planets food producion plants, sabotaging some and infecting others. Finally have the PCs enough about the Maw to find out that...

The Maw is in fact the head of a major guild or even the planetary governer! At this point, start throwing renegade PDF and militia forces against the PCs, backing them up with loyalist forces and other Inquisitorial agents if neccessary. Escalate through a series of pitched battles and set pieces as the entire conspiracy comes to light - the cult inted to infect the entire planets food exports with the blessing of Nurgle. I'd have the PCs taking part in some big cinematic events, like battling through swarms of mutants in flooding sections of the lower-hive, evading giant predatory fish whilst piloting submeribles or even walking along the floor an ocean trench in pressure-resistant enviromental suits.

Ultimately the PCs will confront the Maw only to discover it doesn't possess its full faculties and is being telepathically dominated by a titanic sea-beast. The beast was host to a greater daemon of Nurgle many centuries ago and it was only through the brave actions of another group of acolytes that the beast was bound within the depths a deep sea cave network. Unfortunately, a recent showcasing of an experimental submersible able to withstand greater pressures than ever before brought the person who became the Maw within range of the beast, and the beast was able to turn them into the puppet leader known as the Maw.

By this point i would expect the PCs to be hitting max level, or ascending if you are taking the campaign that far, so i would allow them to call in major support from offworld to confront and defeat the beast once and for all. Or if they are that way inclined, bind it again, banish it to the warp or even use it to their nefarious ends. Essentially, let the PCs have the final call on how they want to try and defeat the Big Bad Boss of the campaign, but make it incredibly hard no matter what they intend to do.

Finally a suggestion on some mechanics:

• If you wish to have large observation windows on the cities, then i agree with previous posts about having laws prohibiting any weapon with a Pen value, any explosives at all, and any of the more exotic weapon types you personally don't want the PCs starting off with.
• Provide the PCs with ammunition, for weapons that need it, that works underwater, with something like a -1 damage rating to offset this benefit. Obviously solid projectile weapons, bolt weapons and some primitive weapons like crossbows can use these ammo types.
• Prevent the usage of Las, Plasma, Melta, Flamer and some Exotic weaponry from being used at all whilst underwater - fairly self explanatory, but firing anything that generates large amounts of heat or doesnt rely on a kinetic projectile will either fail to work or cause major damage to the user. Imagine firing a meltagun and being incinerated in the cloud of steam it generates around the user.
• Increase the availability of all breathing apartus and eye-gear by 1 step. In a world of murky depths and cloying water, nobody wants to be caught out.
• Allow items that affect mobility, such as Jump Packs or Aerial Pinions, but modify them for aquatic usage and increase the cost a little bit. I'm sure your PCs will love the prospect of owning personal underwater propulsion unit like SeaBob here.
• If you haven't already, check out the Hordes mechanic in the sample Deathwatch adventure and the accompanying dev-blog that explains a little more about it. These rules allow you to streamline mass combat and will be very handy later on in the campaign, allowing you to pit literally hundreds of adversaries against your PCs.

As always, i have a metric f*** tonne of ideas floating around in my head so anyone should feel free to PM me or ask here if they want more info on ideas i have proposed.

I think of the mine as something that is actually in work but suddenly have stopped delivering materials to the imperium. The cult has taken the leadership of both the spaceport and the mine. The cult leaders could have come from another planet. The workers in the mine still think that they are doing their work and getting metal. But the truth is that the metal is getting to an isolated room where the cult is building an Soul Grinder (Deamon engine). Is the rules for those in any book? This one could be the monster in the final scene because it is to powerful for the acolytes to beat in combat and it is strong enough to break the walls to hold out the water.

I still like your ideas about the cult name Circle of Distans Echoes and the silent summoning room. The room can be the isolated room where they are building the metal machine for the deamon they are going to summon.

I like how this adventure takes form by the disscusions here. So please, give me more of your ideas.

Got a new one from Kasatka just now when I sould post my message so I had to read that one also. My PCs are just level 3-4 at this point i think so your adventure will be to much for them I think but your ideas are great. I will use your list of equipment in the end of your message. That seams to be logic and fun.

If I can make it a big campaign maybe i will use the rest also.

Here's what I came up with for Spectoris.

http://darkreign40k.com/drjoomla/forum/planetary_data/spectoris_3239.0.html

Coolt said:

Their is some demon machine descriped in "Radicals Handbook". But as your "'Soul Grinder" seems like some chaos fueled mechanic monster I do not think you will find something fitting. ...
...but... if you are into "warp fueled mecha-monster", how about a very oversized Bronzen Malifect? It is a warp construct indeed (see http://www.fantasyflightgames.com/ffg_content/dark-heresy/pdf/dh-previews/Creatures%20Preview%201.pdf for official pictures and stats. Thanks, FFG!).

If you want something more intelligent or with other power, you can use this one as a basic for your "Soul Grinder". Since you do own the GM-Kit, simply apply the size modifiers for stats found their if you want to re-size this beasty.

Idea: Strings of Investigation
First lead could be that long before the strange things started, a new group moved in and bought an nigh depleted deep sea mine (for the Ritual of Distant Echoes which provided the Cult with the plan for the construction of the Soul Grinder). If the pc investigate, they will find the place empty and largely unguarded (possibly some drones but thats it). Anyway, they might find some vox recording device left their and our cables used to position them for recording. And, of course, the deepest of all shafts. With sound proof isolation. Mystery, Mystery

Second lead could be an ever rising number of mining Healots (workers equipped with cybernetic gear to get ore) to having really ugly "accidents". Funny thing is that the while there arms are officially salvaged, they do not seem to reappear anywhere...

Third lead is deep sea mine producing much less ore then expected (it is their that the building of the Soul Grinder takes place. Less work is done here since a lot of workpower is used for fashioning the devil machine).

More ideas coming this weekend on saturday...

Clue: Riots & Violence
A number of worker riots is going on. It started as the worker unrest common for the bad conditions in the deep sea mining and the fact that the majority of the work force is based on the nigh slavery of contract work. Normally, those are just small and temporary affairs but this time they are ongoing and very violent. There are ambushes on guild security patrols and sabotage. The guilds who actually run the underwater city react with curfew, patrols, harsh controls and violence.

With a little investigation [inquiry], the pc can find out that the majority of the latest incidents where accompanied with graffiti or pamphlets of a group naming themselves “Free Workers Movement” left on the side. In all cases, those evidence was quickly removed by guild security and witnesses where intimdated by security and their employers alike to keep their mouth shut.

They can although learn many workers went missing. Some blame the FWM, others blame the Security and others they those missing had to members of the FWM whom got arrested (and perhaps executed).

Note: Choose a difficulty for this test and perhaps other skills ways “Charm” or “Carousing” to get this information. Make it an extended with a low number of successes need (perhaps 5), decide how much time one role takes (perhaps a day or a half day?). If a role is failed badly (three levels of failure or more) the pc end up in trouble with one of the following groups

Violent workers: Some workers are simply against the FWM. They believe they make things worse. By asking around an raising the topic, the workers the pc are talking to believe the pc to be FWM sympathizers or recruiting agents of them. If the pc will be into a brawl with five mining workers if they do not find a way out of the situation (Intimidation; Charm; something else).

FWM Sympathizers: The other way around, the Sympathizers believe the pc to be snitches or undercover security. Only this time the pc are in for a fight which might end with a knife to the gut if they do not successfully claim that they want to join the FWM (Deceive-10; those guys are distrusting). If successful, they will get some a trial mission (sabotage, assault or similar) and will later be introduce in the FWM.

Guild Security: Someone snitched them to the guild security and a group of enforcers show up to intimidate them. If they are caught asking questions again, they will be seeked out again. The pc will receive a beating, become arrested and will receive more beatings while stashed away. If they resist, they will be hunted by the security enforcers in the whole city. If they identify themselves as members of the Inquisition, they will be left alone. But some days later, this information will leak to the cult.

Clue: The FWM
In truth, the FWM is founded and supplied by the chaos cult. The riots they fuel work as a smoke screen for their own operations since all the security and the view arbitrators are busy breaking riots and hunting for saboteurs. And all those missing people are blame to be victims of ongoing conflict between the FWM and the guilds running the city.

If the pc are successful in tracking down a head of the FWM (either by interrogating captured FWM members, gaining their trust while deceiving them to or by shadowing members to a meeting and then following the most affluent dressed on back home) they will find out that the FWM leaders are in truth leading members of one of the guilds. (Lets call the Guild “Domiccian Cartell”)

Another option: After a simple act of violence or assault to test the pc, they will be entrusted with kidnapping a worker later. They are told that he is a “guild snitch” and that the FWM wants to make an example. They are ordered to hand him over outside of the city (and given access to some means to bring him out alive). If the pc plan ahead and follow the people they hand their victim (more air, a vehicle, heat cameras to follow heat trails underwater) the pc will find the hideout.

Clue: The Domiccian Cartel
The leading members of the Cartell are the leading members of the cult. They initiated a cooperation between some other guild security and the Arbitrators to “put down the FWM threat”. Thereby, they where able to tap into information of the other security and will be informed of the pc a couple of days after the identified themselves.
A lot of the operations of the Domiccian Cartell is completely legal, but if some gets hand on their books (claiming to be an official of the Administratum, working with the Administratum or simply breaking into their offices) will show that the their level of activity (mines owned, workers paid, gear bought and landed from the mechanicus) isn´t matching their output. By a degree now profit oriented cartel would ever tolerate. Some of their mines even seem to be operated while actual analysis show that they are nigh depleted and thereby unprofitabel [skill tests for Merchant, Miner, Prospector, to get this information]. This will point to the mine and that something is wrong their.

Option: If the pc break into the offices to get the information, there might be servo skulls patrolling the perimeters (or something lese). The longer they take, the more the chance that they are caught. Ask for checks Literacy to see how fast they are in digging through the information. If they do not pass the routine Literacy test, the patrol will get one Awareness check for every of their check. If the Literacy test is passed, it will be one awareness check for every [2+1 for every level of success) of their checks to dig up the information. Make tables with more success on the “digging part” giving more successful info. But make the pc decide when they want to stop searching.
If the pc have access to the cogitators, this will be quicker. If they do not get the password from an office clerk, the can try to manipulate the cogitator (Tech-Use) or search the place for a password a clerk might have noted despite the laws against it (difficult search test).

Background: Undersea Contract Work
You have to work X year in this place. You get A LOT of money for it. BUT the majority of it is paid in “markers” of the different guild which the guild promises to exchange for thrones on a set rate “once you leave”.
All the shops and housing is run by one guild or another. Most only accept their own markers or that of one or two others. All would accept thrones. Prices are outrageous. Thereby, nigh to all of the money the common workers earn they have to spend on overpriced goods. Thereby, most will leave none a throne the richer. Or they will not leave at all, since the travel from the city to a surface spaceport is heinously overpriced and a travel of world is by itself an expensive affair. Thereby, they have to sign up new contracts with a guild once their old ones are fulfilled.

Disclaimer: All of this takes into consideration that your "Sould Grinder" is based on the malifect and that some augmetics "ripped from their ritually killed owner" are part of all of this.

Thanks for all the advises!

I should start to write a plot for the adventure soon and I will post it here so you could see it and give more advises.

Thanks Gregorius21778 for the link to the Brozen Malifect. I had the pdf before but a major malfunction in my computer forced me to format it. But now I have it again. This is an amasing monster but I think I will just use the stats and make it even worse. I think of an Soul Grinder that is an amfibie machine. It should not just be able to walk because it would just be stuck on the bottom of the sea. It should also be able to work as an submarine with scary arms.

Thanks also to Adam France for your text about spectoris. I haven´t had time to read it yet but I soon will to get mor inspiration.

If you have more ideas just give it to me.

Hi Coolt,

why not sticking with the Octopus Picture here? I think the Octpus was quiet a good ideas In a deep see adventures of Horror, their HAS to be some kind of Octopus. It is like an "upskirt scene" in these japanese girl zombie slasher movies": it´s bad style, it is cheesy, it is campy and we are all much to adult for it... but somehow it belongs there.

Of course, the laws of physic forbid a mechanical construct to swim without turbines and such... but as we started talking "daemon machine" the laws of physic were already out of the airlock, right? Right!

So, have a summoning area where all kind of arms and metal parts (both manufactured and salvaged) are scattered about, each engraved with some unholy symbols demanded by "the pattern". The ritual is kicked loose. I would suggest Khorne or Chaos Undivided; both would somehow allow that simply some DEATH going on in the area would be enough to RRRRelease the Mecha-Kraken! Thereby, if some cultists guard the place and the pc fight and kill them...well some nice scene about the blood droopping from the metal parts, all turning silente and the sound of dropping blood becomes unnaturally loud...and it echoes..and there are ripples in reality (start dealing out corruption point)... which burst and blue-greenish-red lights break through (start dealing more corruption points) and while the pc (hopefully!!!) flee, they can see the metal plarts sliding and swirling towards the rip while connecting..

And THEN let´s see how fast the pc can reach the main shaft up (with stairs along the wall in case the elevator collapses ...which might be the case or it might just be already up and locked there!)

Hey again!

I like the idea of the blood dripping with more and more intense sound the more killing take place.

I want the acolytes to see the machine before it get possessed by the deamon so a acolyte with some lore of tech or tech-use could be able to tell that this machine can be able to both walk and move like a submarine under water. Of course after a successful test. I should just describe it lika a machine with powerful arms, legs and claws and turbines. But they should see it so late that they cant stop the summoning of the deamon.

Another thing is that i want all the old guards in the mine to have been replaced by new ones. All but one. The new ones it from the cult. The one they have missed I want to be an important part in the adventure. He escaped the replacement by pretending to be a miner and then made it out of the mine and into an crashed submarine outside of the complex. The submarine should just be imobilised so it cannot move but all the air filtering and life supporting mechanisms should work fine.

After some investigation and some gathering of rumors in the mine the acolytes can find out about the guard who has escaped. The Tavern should be a good place to look in because its there the miners take a drink after some hard days work. So they can go back to the inquisitor insider. That is the mine worker that the inquisitor has conntact with. He let the acolytes out from the air shaft again to swim out to the imobilised submarine. And it is in that swim tour i want the sabotaged rebreathers to take place.

When they reach the guard he can tell them about the cult and how they have taken the old guards as a sacrifice to the chaos gods.

When they later come back into the mine I start to think if the miner should have been killed just to make an example of what the cult is capable of. To try and scare the acolytes. So maybe the acolytes cant get into the air shaft this time and have to turn back to the guard. The guard in his turn tells them of the sewers exit and gives them a map over the sewer system. So they have to swim in real dirty water but they will get back into the mine and even inte the well guarded fortress of the cult.

what do you guys think of that?

Hi Coolt,

if you want the "machnie host" to be pre-designed to function, you should think really carefull what this function is... and why the cult intended to undergo all those efforts to build a daemon machine for it instead of trusting in more mundane means to achieve the intended ends. If the chaos cult is daemon worhshipping and intended to build a body for a specific named daemon (and the fact that the body is a monster machine was more a fact of pleasing the daemon) you do not need to think to much further.

Otherwise, think about the intentin. If we are talking about "destructing", the thing should be of humungus size. Bigger then a tank and perhaps the size of a real submarine. The daemon could be have been needed then since it was the only way for the cult for power the destruction device. But in that case, your pc will need to have access to heavy weapons, vehicles and/or explosive to handle the threat. Or should be able to call in the PDF! Perhaps their final goal then is to distract the ravening thing, luring it away from the city so time can be bought for an evacuation.

If it was a tool of assasination, it should be much-much smaller in size. But this would not be much fun regarding the "shaft scene".

My plan is that the cult should have bigger plans than just this under water mine. This is just a factory for making Soul Grinders. Than they should be shipped to another planet where they have planned a bigger revolution. But the acolytes will hopefully stop this production.

Of course I want the soul Grinder to be bigger than a tank. This should not be a fair fight. It should be more like - run or die. It should just be there to scare them and destroy the mine because its get mad. And to follow the acolytes up in the elevator when they are chasing the cultist big boss.

Here is a pic of a soul grinder compared to some guardsmen

http://www.games-workshop.com/gws/content/article.jsp?categoryId=cat440204a&pIndex=3&aId=6800021a&start=4