Caverns - Area 1: Excavation Transfer

Caverns - Area 1: Excavation Transfer is the twenty-fifth level of Doom 3. The player advances towards the primary excavation site, where the Hell portal is located. Level 1 contains the oldest, original Mars base. It is also the last level to feature both the non-player characters, and their PDAs.

Summary
Starting off from where Site 3 ended, the elevator takes the marine into Caverns Area 1 - the location of the very first human base established on Mars. He arrives at the Base 1 Materials Transfer point. From there, he heads to the Heavy Lift Transfer while battling hordes of demons, including trites, imps, wraiths, commandos, cacodemons, an arch-vile, and a Hell knight. After unlocking the Heavy Lift controls, he rides the massive lift down to Sub Chamber 2. Throughout all this, the caverns are constantly plagued with tremors and quakes.

Upon reaching Sub Chamber 2, the marine fights his way to Environmental Monitoring, where he finds he needs a keycard to go further. To find the card, he must take a detour to the Thermal Regulation Pump. There are no enemies here, but the marine has to instead navigate his way down a hazardous maintenance shaft which consists of four platforms that continuously extend and retract themselves. He manages to safely make his way to the bottom of the shaft where he discovers a lone survivor hiding behind some pipes. The survivor, J. Katayama, gives him the access card he needs. The marine then heads back up the shaft and returns to Environmental Monitoring (battling a swarm of cacodemons waiting for him outside).

Using Katayama's access card, the marine enters the conference room (where he finds Bob Cody's PDA), and from there, he fights his way to Base 2 Materials Transfer Lift. A lava filled chasm separates this area from his next destination, so he must activate a crane and walk across it to the other side. He then goes to the Personnel Transfer Station and kills the horde of demons that try to ambush him there. He activates an elevator, kills the Hell knight that emerges from it, and rides the elevator down to Materials Handling. He then fights his way to Sub Station 3 Transfer, which will take him to Caverns Area 2.

PDAs

 * Robert Cody. Found in B1 Conference Room 1.

Characters

 * J. Katayama
 * Malcolm Betruger (voice only)

Enemies
The enemy count on Nightmare is the same as on Veteran.

1. Some imps, wraiths, cacodemons and Hell knights are spawned by arch-viles, thus their amount may vary. Here only the number of distinct spawn points is shown.

2. Two Hell knights have lower health than standard, 500 and 600 instead of the normal 900.

Weapons/Items
The item count on Nightmare is the same as on Veteran, except the med kits are absent. There are no changes in the amount of items in the BFG Edition. There are three health stations on the level, one with 82 health and the other two with 32 health in reserve (all of them have 100 health in BFG Edition).

Secrets

 * In the very first room there's a hole in a floor with armor and grenades in there.
 * In Base 1 Junction 1 there's a small shell box hidden in a pile of rocks.
 * In Have Transfer Lift 1 there a gap between the lift and the platform with the ladder leading inside it. There's small passage inside this gap with a chain gun, ammo, and armor.
 * In Environmental Monitoring there are a couple of clips hidden on top of some machinery boxes in the center of the room.
 * In Sub Chamber 2, when the player has to climb the ladder to the top of the building (to get the access card), the player can jump off said ladder to access the roof of the lower level of the building and find a plasma gun with ammo there.
 * When the player exits B1 Conference Room 1, there's a ladder on the left hidden in a dark area. Upon climbing this ladder a wraith will attack the player and a door to a maintenance hatch will open, revealing a cache of ammo.
 * After the player uses the crane to get to the other side of B2 Material Transfer Lift, some items will be hidden inside large metal pipes in the area.
 * In Personnel Transfer Station there are a few items hidden behind the crates; besides, one of the crates is open on the top and can be jumped into and will contain some ammo.
 * In Materials Handling there are some supplies hidden behind explosive barrels and more supplies hidden behind crates in the area.