Ok, so I'm running the House of Dust and Ash, and I'm looking for some advice to make my adventure more scary for the players. I get the impression they aren't scared so much as prioritizing who is dangerous and who isn't. I want them to think that everyone is dangerous, aside from the scribe, he's their best buddy (who happens to have lots of useful knowledge skills that the party lacks).

My party just got to the island and got their rooms. They've met the contact who told them about the trepanned soldier and vox problem. They've talked to Master Nonesuch. He's high on the "dangerous NPC" list because of the inexplicable feeling of dread the Abitrator felt. They've figured out that Rubio is a fraud and Maygar is just another Rogue Trader looking for stuff to buy.

They also know that the Abbott is a psyker, but aren't entirely sure of his loyalties. I had the Tech priest recognize the bandaged cultist Arko as a wanted heretic. Later, Arko picked a fight with the guardsman and ended up getting arressted by crewman and thrown overboard for attempted murder. The abbott denounced Arko, of course.

And the arbitraitor doesn't know whether to trust Octavia Nile or not. Her assasin poisoned his drink and Nile 'accidently' spilt his first drink so that he would get the poisoned drink. Being extremely suspicious, the arbitrator only drank a sip, so I ruled he didn't get too sick. He's just not sure if she was trying to poison, or if she spilt the poisoned drink. But, now he won't drink anything someone else offers him.

Vymer and Quill are possible acolytes from a different inquisitor. Or bounty hunters.

And FYI, my party is an arbitratior, a guardsman, a pskyer (biomancer), and tech-priest. They in the middle of rank 5 and I let them take whatever equipment they wanted for the highlevel adventure. So the arbitraitor has carapace armor and a collection of sp and las guns. The guardsman has a melta bomb and melta gun training. He doesn't have a melta gun ... yet. The psyker knows must of the minor powers along with the healing powers, ball lightning, siphon toxin, and the power that lets him have dark sight, flier, etc. And the tech priest has a bolter and bolt pistol plus utility, optical, ballistic, and heavy lifting mechadendrite.

Currently, the tech priest was going to break into a tomb to get a skull for a servo skull. He changed his mind when I mentioned the gun servitors. And the guardsman was wandering around the crypt area when the abbot cast Inflict Pain on him. But he resisted the power The arbitrator and psyker are meeting new people and checking them for psychic talent.

So anyway, suggestions are appreciated at this point.

Well mate, you could do something that requires a degree of testicular fortitude.

In the middle of the night have them hear a scream and see Nonesuch, without his flesh-costume, running away, brain in hand. If they try and pursue, then have Nonesuch's helpers and/or the Logician Agents, possibly other characters, "accidentally" trip into them (Agility Tests all around) . Afterwords, when they go into investigate, they find Whent (the scribe) dead with the top of his cranium removed. If his friend is alive, then maybe have him die instead. Either way, the survivor is driven insane and starts shooting at anybody who comes through the door, forcing the Acolytes to have to talk him down (if they don't do the ruthless thing and kill him first, albeit if they do that you should apply Corruption Points).

After that, suggest to the Acolytes they may want to post watches outside people's doors to ensure no more schenanigans happen. Of course whoever gets left in the room is then attacked by the Abbot's summoned deamons (if they have any sense they'll flee the room, otherwise I'm expecting Fate Point burning).

At this point, if they aren't scared or disoriented enough, then the next day you should have them come back to their room to find it ransacked. Don't make it too obvious, but have Octavia then start behaving a tad bit more coldly towards them. They can't prove anything at all, which will frustrate them, and what's more they'll know that she has the ability to get in and out of their rooms without anyone knowing. If you wanted to be even eviler you could have the Ashen Tear Assassin sneak in the night after the ransacking and attempt to mind-scramble one of the sleeping Acolytes (if you want to be really evil, burn the fate points!), followed by another chase which they most likely won't win (Ashen Tear being immune to the Biomancer's powers seeing as how she's mainly mechanical, while her high agility rating and bionic legs means she'll be able to outpace anyone).

The daemon one alone usually does the trick when used properly. In one game I ran, my Acolytes were being woken up a number of random nights to find some sort of creature from hell trying to kill them. Then the Black Priest realized that it might be a good idea to install some Pentagrammic Wards on their cabin . You should see the looks the Priest got when the Acolytes realized that he could have been warding them the whole time, but didn't think of it.