So, I'm wondering what sort of options a Rogue Trader might bring to bear to try and persuade an Inquisitor to not liquidate them. Here comes the long, wordy scenario:

Tau have begun to invade the Expanse, and the Battlefleet isn't entirely prepared for it. While Aedan Qel-Drake leads the effort to stop the insurgent xenos, Inquisitor Ursula Von Cosrath, after returing to this part of the galaxy from the Jericho Reach, chose to install herself aboard Isabella Artymus' flagship, the Artemis Resplendent , both because the smaller vessel is much stealthier, and because Lady Artymus is more free to assist the Battlefleet, and less in cahoots with other xenos. Thing is, the Inquisitor, while on good terms with the likes of Ebongrave, is, in actuality, a Radical Inquisitor, and one among the Oblationist Faction. Basically, they believe in using the enemy's technology against them, and then eliminating everyone who saw it, as only they, themselves, are strong of faith enough to resist the taint of the xenos technology; many actually plan their own deaths, even, as xenos tech is all-corrupting.

Well, here's the problem: I'd rather not just have Von Cossrath pull a pulse pistol on Artymus, or blow her ship up. What are some good ways to "persuade" the Inquisitor to not wipe you out, after she used you to defeat her enemies, that won't bring ALL of the Inquisition down on your head? She's Radical, and the Warrant of Trade does, to some degrees, allow a Rogue Trader, uniquely, to deal with such things, but I'm not sure how to stop her from just "getting rid of the evidence", once the Tau threat is eliminated, even if Artymus is in well with the Navy, the battlefleet, and numerous important Calixis organizations; "accidents" happen, out in the void. Any ideas would be great. How best can a Rogue Trader dissuade an Inquisitor?

End of the day, the only group that can officially handle the Inquisition is the Inquisition; if your group is unable or unwilling to arrange an accident, tragedy, or negligent discharge of a firearm, you need to find someone to pull rank on an Inquisitor sizing you up for a pyre. A big question is how much the group knows of her alignments and methods. If they find out she is an Oblationist, they can safely finish her and ship her corpse to the Ordo Xenos with a note that your dynasty expects to be fairly compensated for doing the Ordo's job for them. If they do not think they can take her or there are too many Imperial witnesses, they can send a message to both the Ordo Xenos and Ordo Malleus; file an official report with her superiors concerning your suspicions of her allegiances and methods. Make sure to attach an addendum offhandedly mentioning you also contacted the Ordo Malleus, to short circuit the knee-jerk response of the Ordo Xenos to rub you out as well to save face. The Ordo Malleus usually takes point on all radical Inquisitors if it seems their own Ordo is not bringing them to heel in a timely manner, but make sure you have all your ducks in a row. The responding Malleus Inquisitor will give your dynasty a good once-over on general principle, and will not be dissuaded by practicality or circumstance. Pretty much any Malleus Inquisitor not under cover or traveling with a crusade or expedition will show up with their own capital ship and military contingent, and no orders or inclination to respect the Warrant of Trade.

I had my players deal with the Inquisition by making them come to her, without realising it. Since "Profit Factor" is a representation of various business ownerships under the control of the Rogue Trader funnelled through Imperium bureaucracy I deployed an auditor of the Imperial Estates to freeze their funds until it could be investigated.

One INCREDIBLY FAST warp travel later, they barged into the Adeptus Terra office to be informed that the funds would not be released (did you know that Ascension Adepts are immune to all forms of persuasion? They didn't) until the audit was completed in 10 Solar years.

Unless this helpful Inquisitor could help you cut down the red tape of course.

Out in the Expanse the Inquisitor is in dangerous territory. If She's on your ship than she needs YOUR Astropath to communicate with her Ordo. (Unless She happens to be towing one along for good measure!). This means she easily could "go missing" and no one would "really" know the truth. This is a dangerous path to take though since there might be spies and informants among your crew! Of course she knows this and would be loathe to act openly against you out where the RT holds the better hand. Additionally, most Warrants give the RT greater latitude when it comes to Xenos technology.

Basically, out in the expanse, you might reach a sort of detente. She won't want to move against you because she is probably outnumbered and outgunned. You probably won't want to move against her due to likely later repercussions. When it come time to return to Imperial space though, I recommend putting her on a separate ship and making port somewhere other than where she does!

She might even appreciate your 'delicate' extrication from the situation but that depends on her personality type (Does She view herself as an "honorable" warrior who would appreciate a cunning foe? Or is she a complete tool who will become obsessed with hunting you across the galaxy?!?)

And never forget the importance of remaining useful. An Inquisitor might - with regret if he or she is a good Imperial - feel that it is necessary to ensure that a tool that has seen too much can't corrupt the rest of the Imperium, but should hesitate if that tool is still useful or even vital. For as long as the Imperium truly needs you, you have a good chance of not being sacrificed on the pire of the Great Cause.

Out in the Expanse the Inquisitor is in dangerous territory. If She's on your ship than she needs YOUR Astropath to communicate with her Ordo. (Unless She happens to be towing one along for good measure!). This means she easily could "go missing" and no one would "really" know the truth. This is a dangerous path to take though since there might be spies and informants among your crew! Of course she knows this and would be loathe to act openly against you out where the RT holds the better hand. Additionally, most Warrants give the RT greater latitude when it comes to Xenos technology.

Exactly this. The Inquisitorial Rosette's authority is vast, and all-encompassing. But ultimately, it's a pretty little piece of jewellery and a limited argument against a reinforced platoon of household armsmen.

Having a backup plan to kill the inquisitor is just as feasible as the Inquisitor killing her.

Equally, An Oblationist is - or should, at least - still retain a degree of pragmatism. Yes, they're 'hard-line' radicals, who believe in sensible degrees of self-policing, and even self-destruction to avoid corruption. But they're still radicals, and to acquire all their shiny xenotech and similar forbidden stuff they need access to the cold trade and the black market. Because going and getting it themselves isn't feasible, as it distracts from doing their job - protecting Imperial domains.

So killing off every witness is great in theory, but then you have a problem laying hold of toys next time you want something shiny.

Equally equally, the Oblationists are radicals. There are plenty of Puritan Inquisitors who'd be happy to hunt down and destroy the deviant. Of course, shopping Ursula without simultaneously convicting yourself will take a bit of skill (blind tip-offs, creative "accidental encounters") but is doable with enough resources and motivation.