The Remains of UAC is the first episode of ZPack - Random Maps for ZDoom. The episode is the easiest of the three ZPack episodes, and is composed of maps that largely take on a techbase or infested techbase theme.
When the pool of submitted maps to the ZPack project started growing large in size, the team began discussion on just how the maps should be organized. While ideas such having a central hub and allowing the player to choose maps in any order where tossed around, the correlation between map theme and difficulty was noted by some contributors and eventually a set order divided roughly by theme was settled upon. As the submitted maps began to reach a peak count it was then decided that the sets should be turned into episodes. All the easy, shorter techbase themed maps were pooled together for this first episode.
Aside from taking the player through a diverse set of techbase designs, this episode contains other notable ventures such as: an enhanced remake of TNT: Evilution's first level (E1M1), a time-limited rocket launch abortion mission (E1M3), a base set in an snowing arctic wasteland (E1M6), and a two level mission in a large, demon overrun power plant guarded by the episode's final boss, the Terminator, designed especially for ZPack by Björn Ostmann (Vader) (E1M8 and E1M9).
- E1M1: Vestibule by Captain Toenail
- E1M2: Blast by Phobus
- E1M3: KDIZD Launch Site by Daniel Gimmer (Tormentor667) & Björn Ostmann (Vader)
- E1M4: UAC Waste and Storage Facility by hnsolo77 (Exit to secret level)
- E1M5: Site X by Captain Toenail
- E1M6: Glacier Base by IcyTux
- E1M7: Nuclear Sky by Daniel Gimmer (Tormentor667)
- E1M8: Thunderpeak Powerplant by Björn Ostmann (Vader)
- E1M9: Termination by Björn Ostmann (Vader) (Boss level)
- E1M0: Colossus Reloaded by Björn Ostmann (Vader) (Secret level)