Central Processing: Processing Distribution Center

Central Processing: Processing Distribution Center is the twenty-second level of Doom 3. The effects of the twisted demonic growth in the base are evident here. The player meets a wounded Campbell for the first and last time here. The level is described in-game as a transitory level which connects Delta Labs and the original Mars base, and somewhat serves as a power and data storage for the latter.

Walkthrough
Walk a few steps, and an Imp will break the window on your left, leading to a cabinet, an Health Station, Shells and a door. A second Imp will teleport near the start of the level. The locker's code is on a PDA from the previous level. It contains a Rocket Launcher, a Rockets box and a Grenades box. There is also a Box of Shells and a monitor revealing a Security armor.

The next room is big ; it is the main room of the level. It contains a huge demonic growth in front of you, a closed door on its left, a desk on its right containing another Health Station, a passage to the left and a door to the right. Kill the Wraith and take this door.

You are in a fiery corridor with tiles floating above lava and giant skulls and bones scenery, for the first time in Mars base in the game. Follow the path, which lead to a tiny sas and then a dark office room. You'll have to kill 2 Imps and some Trites here. After this, venture in the dark office. There is a monitor on the right side which control some cameras. Beware as activating one of them will make a Trite crawling from behind the screen. Another camera gives a code which will be used to unlock a door in the main room. Explore the rest of the room : at some point, a Tentacle Commando will teleport in the sas room. After killing him, a second one will appear near the end of the room, where there are some ammo in a shelf and a monitor opening a small maintenance hatch a little bit back. It contains Bate's PDA.

As you return to the main room, Trites will crawl from the floor. There is a corridor in the bottom of the room, but beware as a jumping Cherub is waiting for you behind the corner. Once he awakes, two other Cherubs spawn in the main room, so be aware. The corridor contains a total of 3 doors on the left. There is an Imp behind the first one, some ammo behind the second one, and the last one is locked with a code. As you approach it, an Arch-vile will appear before you, summoning Cherubs from the main room. The code can be known thanks to the camera monitor in the dark office. It is 627. Note you can go here right at the beginning of the level, skipping the dark office room.

Behind is a corridor. On the left you can see some ammo in distance, above another lava pit. On the right, the corridor will crumble to become like the the one leading to the dark office, being swallowed by lava and having some levitating tiles. This demonstrate how the technology collapses against Hell.

It leads to one of the most annoying section of the game... A somewhat "U" shaped dark corridor stuffed with server banks, filled with Cherubs... Walk a bit to the right, until you see, on your right, an elevator door. Walk carefully as niches will open on the left side, releasing a Cherub, and two of his brethren somewhere further in the corridor. You have then a choice: take the elevator and ignore the rest of the room, or explore the rest of the room, giving some challenge and rewards. In the turn of the "U", there are some Armor Shards ; picking them will cause the wall to open, revealing an immediate Imp. Next to this, you can see a pulsating light on the roof. Walking under or near will open another niche, releasing an Imp and a Wraith behind. At the end of the corridor, there is a door on the right and PDA on the left. Approaching it cause a Wraith to come from the door and a Cherub from the darkness behind. Once all is calm, you can pass through the door, to reclaim the items you saw in previous corridor: an Ammo Belt, a Rocket Launcher and an Armor. Returning cause an Imp and a Tentacle Commando to appear in the darkness of the corridor. A final Cherub duo appear near the entrance of the room.

The elevator leads to the upper floor, with useless niches around. There is a Wraith to welcome you. Continue and an Arch-vile will teleport in front of you, summoning Cherubs (the first one being right behind you). Kill them all and explore the rest of the room. Behind the Arch-vile's burnt pentagram is a circular corridor, leading to another elevator. The right side abrits 2 Wraiths and the right side an Armor, a Stimpack and a Grenades pack. Approaching the elevator causes 8 Trites to crawl out from holes all accross the circular path.

The elevator leads to another server room. You have to face an Imp and several Cherubs here. If you approach the exit door, an additional Imp will surprise you from either left or right side, and it will be no long before a Tentacle Commando and sometimes an additional Cherub comes across the door.

The door leads to a "L" shaped room, with some spikey growth in the middle. Walk a few steps and a niche will open in both left and ride sides, revealing an Imp each. Walk towards the dark desk room, kill the Tentacle Commando who'll run at you, enter this dark section, kill the two Imps and lone Cherub that will teleport around, continue and take the door.

You are in a small corridor, again. Watch out as you walk as an Imp will come from front. Walk until the desk. The music, the bonuses and the somewhat upbeat music fortells what is upcoming... Grab the ammo in the locker (the code is in the PDA from the "U" corridor on 1st floor), ready the Plasma Gun, then pick the blue panel on the shelf. Trites will crawl from the sides of the room and two Imps will also appear. If you run a bit, an additional Arch-vile will teleport here, spawning Cherubs. It would have been the perfect battle for the BFG 9000, but sadly it is impossible to bring one here. The tip here is to climb on the crate with the Medkit (or one of the nearby crates) and take out Imps and Trites, and then, to proceed further to take out the Arch-vile and his Cherubs without adding them in the Trites and Imps mix.

Once the room is safe, pick the rest of the bonuses you left, and backtrack. In the "L shaped with spiked growth" corridor, you'll face 2 Cherubs (in the dark spot). The next room is safe. Once you down back in the circular path, you'll have to face a semi dozen of Wraiths at once ; once again, taking cover in the elevator is not so bad. Return in the main room and place the panel where it is needed. An Imp will appear as you enter the main room (actually, he's meant to teleport here if you return here after having killed the first Arch-vile of the level).

Behind the door is an empty corridor with 2 doors. The little side one leads to a Medkit, and a Trite will come from the roof as you return. The big front one leads to 2 final Imps and an elevator.

Once out of the elevator, simply follow the path leading to Campbell. He quickly speaks and dies. You then hear Sarge taunting you. There is a hole on the ground, leading to a cache with a Medkit, Shells, an Ammo Belt and a Large Cell pack. Then, you can take the exit door to Main Processing.

PDAs

 * Tony Bates
 * Charlie Haskell

Characters

 * Jack Campbell
 * Thomas Kelly/Sabaoth

Enemies

 * Former Humans
 * Commandos
 * Demons
 * Imps
 * Wraiths
 * Cherubs
 * Arch-viles
 * Trites

Weapons/Items

 * Grenades
 * Shotguns
 * Rocket Launcher

Cabinet/Door Codes

 * Storage Cabinet #452: Heavy Weapons - 571
 * CPU Lab A - 627
 * Storage Cabinet #009: Storage - Already Open
 * Storage Cabinet #669: Ammunition - 468