Dark Covenant is a PWAD I've seen bandied about as one of the lost classics of 1996. It's a twelve-map episode for Doom II, released by one Keith Phipps. DARKCVNT has no real story, but it kind of runs as an analogue to Doom II's main story. The player wakes up in his or her house, only to find that demons and zombies are everywhere. It's a mad trek through sewers, a ruined city, and caverns, eventually ending up at a UAC facility that takes you to Hell and back again before reaching one of those world ships that the Hellspawn were holding hostage.... It never really occurred to me how ridiculous it was that Hell was holding the Earth's escape fleets hostage with a single button. I mean, it's obviously their rules since they're warping reality, so maybe the device in "Circle of Death" is some kind of Hellish warp interdictor.
