Delta Labs - Unknown: Union Aerospace Research Division

DELTA LABS - UNKNOWN - "The Delta Complex is the most advanced research facility on Mars. Sector 1 contains the power systems, energy core distribution center, and services the administrative functions of the entire Delta Complex."

Delta Labs - Unknown: Union Aerospace Research Division is the eleventh level of Doom 3: Resurrection of Evil. The player fights through parts of Delta 3, Administration, Delta 2B, and Delta 4 from Doom 3 that have been corrupted by Hell.

This is the most unique level in all of Doom 3, because the entire Delta Complex is in constant dimensional flux with Hell and shows a horrifying alternate version of the area every few seconds, warping the player's vision. Bloody skeletons appear when in flux with Hell and can be interacted with until the flux stops. In the BFG Edition, this dimensional flux has been removed altogether.

PDAs

 * Patrick Hook

Characters

 * Malcolm Betruger (voice)

Enemies

 * Former Humans
 * Flaming Zombies
 * Hell Zombies
 * Demons
 * Revenants
 * Hell Knights
 * Vulgars
 * Ticks
 * Forgotten Ones

Weapons/Items

 * BFG 9000
 * Grenades
 * Bullets
 * Shells
 * Clips
 * Ammo Belts
 * Plasma Cells
 * Rockets
 * BFG Cells

Cabinet Codes

 * Storage Cabinet #116: Supplies - 634
 * Storage Cabinet #117: Supplies - 634

Trivia

 * Not all places that are revisited here were located within the Delta Labs in Doom 3 (e.g. the room of the Demon introduction cutscene from Administration).
 * The main portal is shown active as seen in Delta 4 and not deactivated as later seen during the Delta Complex map. This, together with the existence of fresh bodies, zombies, and a recently-dated PDA, all indicate that the Delta Complex had not been abandoned, but that Betruger's latest invasion has warped it worse than Erebus or Phobos, most likely due to the existence of the teleporter to Hell within it.
 * The room with the tanks where demonic specimens are kept is visited at one point, except that the tanks are now all empty, possibly suggesting that research on the demons was halted after the events of Doom 3.