Hey all! Long time lurker and friend of
@prewarsalad being encouraged (read: kicked via the internet) to join in with this.
Firstly, this sounds like an awesome idea! It's been ages since I've played Inquisitor and I've wanted to do a proper narrative-focused weekend of it for yonks.
Some musings and ideas setting-wise (which are obviously only suggestions):
At the moment a horror-survival theme seems to be grabbing people here. I think that works especially well for Inquisitor as you can explore the side of the 40k universe where's its not a power fantasy with all the resources you need whenever you like it. To that end, the main story problem in horror is "why can't our characters just turn around and leave/why go into the haunted mansion in the first place?". As a suggestion, here's what popped into my head when I read your awesome ideas:
Our characters are all scattered across the galaxy. Maybe they have ties with each other as rivals/comrades/enemies, maybe they don't. What's important is they all find the shards of a Chaos artefact (which they want to destroy/cleanse/harness for themselves). As they claim it there's a blinding stream of warp energy that engulfs them and their retinue. They open their eyes to find themselves transported away into the belly of a spacehulk hunting for an escape route - and they're not the only things hunting...
I quite like the idea of a spacehulk over a mine in that spacehulks are really, REALLY weird. In the background, they're more than just big ships - they're the smashed together remains of countless vessels that have been melded together by the warp tides. For gaming purposes this means we could do a huge mismatch of terrain that's linked by twisted wreckage. It also gives us the variety of doing tight corridors and then pockets of open areas that used to be manufactorums or chapels or bio-labs or even weirder stuff from all races. I can totally imagine places in it where the laws of reality are bent by the warp - low/inverted gravity or time loops etc.
For narrative purposes, this gives us a reason why our characters need to press on forwards and explore. I imagine the end scenario being a race to a teleportarium that can send our characters back home but only if they have the shards of the artefact with them. To complicate things, there can be more shards around than all our characters have in their possession. We could have NPCs that have survived in the spacehulk for years waiting for the last shards to arrive and the teleportarium has only just activated when we arrive. They could be anything from Chaos cultists wanting to harness their power to a lone Astra Militarum soldier who's sanity is hanging by a thread. The big roaming threat we could have to avoid could be a horde of degenerate cannibals (using the Flesh-Eater Court models) - men and women of the Imperium that have been driven insane by the warp.
So basics are: normal(ish) retinue thrown into extraordinary place; can't call for backup against huge threat; each have a key (or part of a key) to leaving giving us plenty of opportunities to work together/steal from each other/backstab each other at the last minute.
What do people think?