Delta Complex: Union Aerospace Research Division

"It's up to you now. Take my PDA, it's got what you need. Good luck."

- Elliot Swann

Delta Complex: Union Aerospace Research Division (also known as Delta Labs Sector 5: Union Aerospace Research Division in Doom 3: BFG Edition) is the twenty-first level of Doom 3. From hereon, there will be no more zombies other than commandos. The ticks make their first and only appearance.

Summary
The marine arrives back at the main portal in Delta which shuts down soon after he arrives. Betruger addresses the marine claiming that he is too late and that Hell no longer needs the Delta teleporter. The Hell Gate will bring millions of demons to Mars. Once the fleet from Earth arrives, Betruger and his minions will seize their ships and use them to invade Earth.

Once more the marine has lost his weapons on the journey back from Hell (with the exception of the Soul Cube) and must collect them all again. He journeys through familiar parts of the Delta Complex, and eventually comes across a wounded Counselor Swann. Swann tells him that Sergeant Kelly has been converted over to the demons' side and is no longer human. Campbell has gone after him. Swann tells the marine that the Hell Hole resides in the underground caverns and that it must be closed before the fleet arrives. He gives the marine his PDA which will allow him access to the CPU complex.

The marine makes his way to the entrance to the CPU complex, fighting arch-viles, commandos, and a revenant along the way. After he defeats all the enemies, he uses Swann's PDA to gain access to the CPU complex.

Objectives

 * CPU Complex
 * Using Swann's PDA gain entrance into the CPU Complex

Characters

 * Malcolm Betruger (voice only)
 * Elliot Swann

PDAs

 * Elliot Swann. Found near Counselor Swann.
 * Bruce Jackson. Found in Delta Main Lobby in one of the corners, with a severed hand next to it.

Enemies
The enemy count is the same on all skill levels. There are no changes in the enemy amount in the BFG Edition. * Some of the tentacle commandos are spawned by the arch-viles, thus their amount can vary. Here only number of distinct spawn points is shown.

Items
The item count is the same on all skill levels. There are no changes in the amount of items in the BFG Edition.

The player starts the level with the Soul Cube.

There is one health station on this level, but it has 0 health in reserve (it is implied either that the player has used it all while being here before, or it was used by Campbell and Swann on their way through Delta; this health station, however, does have 100 health in BFG Edition).

Secrets

 * There's an armor suit hidden amidst the fleshy growth in one of the corridors in Delta Main Lobby.

Trivia

 * If the player jumps off the destroyed bridge and falls to their death, Betruger will be heard laughing.
 * This level is referred to as Delta Labs Sector 5 in the save and load game menus. This seems to be an oversight, as there technically is no Sector 5 of the Delta Labs.