Your trapped on that infernal moon base as usual. You've gotten to the point where you take out most everything that comes at you without blinking. You've become careless. You round a corner and meet a hail of fire and gunshot, and you're dead. You wake in a dark hole, awaiting the time when the denizens of hell will come and take you away for a permanent more-than-luke-warm bath of fire. BUT HEY! Just because you're dead doesn't mean that you can't still kick butt! After all, going to hell for real didn't take away your shotgun (and they say you can't take it with you). You scrounge your way out of the dark hole and see a fortress in the distance. If you can reach it, then you can reclaim your lost soul from it's round blue container and free yourself from Purgatory.