Doom 3/Alpha Labs Sector 1

After transfer, enter the reception ahead, and head directly to the terminal on the right behind the desk. Activating it will light up the area, making it easier to engage the zombies.

The Blue 16 door leads to the Atomic Stabilization Hub. One shotgun Z-Sec should be near the door and you may be able to attack before he reacts. Two other Z-Secs are to the right, taking cover. Proceed left. Opening the Blue 17 door has a crouching imp ready to attack, and released another zombie from the main room. Two more Z-Secs approach from the Blue 18 door on the opposite side of the EPD Observation Platform.

Enter the EPD Lab. You will be attacked by Imps. Head to the control room, where the screen turns red, after which three imps will attack. Head to the console that allows opening the repair gate. There will be plenty of attackers soon after the screen turns red, especially from dark corners. If you get injured, there's a health station with 73 units. With the repair gate open, you can advance, but be sure to duck under the beam to avoid damage. The chamber has a conduit that can be opened to exit, although there is a Z-Sec waiting outside.

In EPD Junction 2, the way forward is blocked by two flame jets. Head down the corridor opposite these jets to the EPD Particle Emulsifier. A few enemies later, you should reach a console to seal the leak, and head to the EPD Particle Scrubber.

The EPD Particle Scrubber will have one Z-Sec running from the door ahead. Approaching the door opens a storage closet behind with one Imp and one Z-Sec. The platform below has armor, with an imp released from infront of the armor.

Going through the door to the EPD Contaminant Purge will start the cutscene introducing Maggots. They are easily defeated with several bullets. When they're finished, you can go through the floor and into the crawlway. The first exit allows you to proceed, while the second only contains a medikit and a few clips.

Alpha Labs Junction 3 has a few enemies, simply head to the Hydrocon Condenser. In this room, the floor sometimes gives way, only serving as flavor rather than being a threat. In the Oxygenator, watch for two barrels being thrown, and two enemies on the upper floor. Back in the condenser, the stairs will give away - if they do but you're on the wrong side, you can jump and climb its railing.

In Hydrocon Junction 1, you're attacked by two imps, one in front and one from behind. Head to Hydrocon Siphon, and climb the ladder. You will reach G. Kreitman, he tells you not to shoot the glass, but you can continue and collect Bernie's PDA to open the Hydrocon Control door. A few enemies are past the door, with imps in the hydrocon lab. A health station with 44 units is just before the Alpha Labs Main Junction.

Door Blue 19 leads to a dead end, turn right to doors Blue 20 and 21. One maggot appears. Blue 22 is the final door, with several maggots attacking at once, and the elevator being just ahead.

PDAs

 * Kyle Berger: At EPD Lab.
 * Jack Smith: At EPD Particle Emulsifier.
 * Bernie Lipsitz: At Hydrocon Stabiliazation
 * George Krietman

Video disks

 * Elemental phase deconstructor: In EPD Lab, in the control room.
 * Hydrocon: In Hydrocon Control.

Cabinets

 * Storage Cabinet #009: 752.
 * Found in EPD Lab, code learned from Kyle Berger's audio log.
 * Contains a clip, security armor, grenades and two medikits.