Morning/Afternoon/Evening folks of the board.
I'm working on a new campaign, putting the ideas together for something new to throw at a group of unlucky chaps I know of and wanted to put some of the concepts past you lot for brainstorming. I'll outline the intended plan, if any of you have ideas for refinement then I am happy to take them. The premise in my head stands thus:
Act 1 - Greetings
An Imperium world (back of beyond type place) is under constant raids from Tau (or probably Eldar, I havent decided). Unfortunately the terrain favours their faster lighter vehicles and the Imperial Guard are finding themselves bogged down in marshy unstable terrain to be picked off by Hammerheads (Or Fire Prisms) and are losing ground by the week. The resource value of the world means that it is not deemed suitable to withdraw. I wont explain why the other faction are there yet though. The Deathwatch get called in, two squads. One is the player, the other is an NPC group of senior rank to act as leadership.
A few sessions then will see the team either countering enemy raids and incursions or performing recon and counter attacks to try and push the war into Imperium favour. As the superior tactics and resources of the Ordo Xenos give the opportunity. At present the Imperium can barely hold its ground let alone counter attack. Throughout the act though, hints are going to be placed regarding warp disturbances, messages not getting through from Astropaths etc. At the end of the act they all find out why.
Cue Tyranid tendril a-la Dawn of War 2.
Act 2 - Questionable Judgement
The Tyranids will drop to the planet in full consume mode as they always do. With this third enemy on side, the conflict starts to strain both sides. Contact to the rest of the Imperium then becomes severed. With too many to cope with, both the Tau/Eldar and the Imperium start to suffer even worse losses. The two sides get rapidly exhausted and losses increase, but there will be two distinct surviving groups. The Deathwatch group and the main group of the Tau/Eldar become the last two main surviving camps.
This will eventually face a massive upheaval when their allied group of Deathwatch marines will end up losing their commander by a particularly potent Lictor, leaving the group leaderless.
At this point I want to basically leave them with a difficult choice. Both the players and the Tau/Eldar are both struggling to stay alive and rapidly taking casualties. An offer of a ceasefire will be encouraged but not forced by me. I want it to feel natural. Here I anticipate some difficulties, as they could opt to say no and go it alone. I don't want to force them to accept the alliance though either. If they accept it, both teams get to benefit from each others shared resources to try and survive the continued Tyranid infestation and pool resources to develop a counter attack. If they don't then it still needs to be possible for them to survive alone and get help.
Act 3 - Conclusion
If they sided with Xenos: They find out the reason for them being there. The Tau want a gigantic reserve of Iridium and precious metals enough to fund an entire sphere of expansion. The Eldar meanwhile, probably some sort of relic/artifact of value. They then need to work together to either find a way off world or to force the devourer away.
If they opted to go alone: They obviously don't find out the above and have to find the rest out themselves. How to get off world and probably save any Imperium assets which are still trapped on world.
I open the floor for feedback. Note that much of the above is bare bones, not a lot there yet. Suggestions?