system
Given the following post, respond as if you're commenting on Reddit:
human
[Warhammer 40k] So I discovered a Lost Colony....

Hi, I'm a Rogue Trader that has rediscovered a colony that was supposedly lost during the Age of Strife by following some old maps that I bought from an antique collector. I as expecting to find nothing, or maybe a primitive feudal world, but instead when I got there I found a bustling Hive World-looking place. All their stuff is super-shiny and reeks of xeno-tech, but they say they built it all themselves! Apparently during the age of strife they killed all their psykers and banned all warp-related technology when they lost contact with the Imperium, and they just assumed everyone else was dead. Now here is the real kicker: they said they have a fully intact STC(!) and have been *improving on it for the last 10,000 years*. The only bad thing I've found so far is that they've stopped worshipping the Emperor and aren't keen on starting up again. Something about it "being the exact opposite of what he wanted". They were incredulous when I mentioned the Ecclesiarchy, actually.

So my question is this: What do I do with this information and how rich am I about to get? Also what's going to happen to these guys?
gpt
Well, you have two basic options.

Firstly, you can exploit the hell out of them. If their technology is that advanced, trade could prove awkward - but if they're anything like regular humans, they'll be interested in foreign cultures; you should be able to trade music, vids, literature etc. for some extremely lucrative tech. Just make sure you sell it on well away from the prying eyes of the Machine-Cult, and you'll be buying your own gold-plated battlecruiser within a few years.

Secondly, you could sell them out - alert the Ecclesiarchy and the Adeptus Mechanicus, then try to charge through the nose to transport Missionaries and Magi to this new world. This will be less profitable in the long run (not least because the world will almost certainly be targeted by a crusade within the next couple of decades), but much safer for you.

If you do choose option one, it would probably still be a good idea to put down some missionaries (although it might be in your interests to find the most ineffectual and/or corrupt churchmen available), so you've got a defence in place for when you or your heirs are inevitably found out.

Whatever you do, eventually the Imperium will find this world. And then probably invade, unless they're willing to give up all their heretek and also to embrace the Emperor's light.