Walkthrough for Level 8 of Doom 3: A Complete Walkthrough Guide to Alpha Labs 4 – Doom 3 Walkthrough

Reactor Ready Room

Exit the airlock and use the medical station if you need it. Through to the left you’ll find a scientist, L. Kaczynski, trapped in a chamber who’ll ask you to help him. Hit the control panel to open the door for him then head through the door and take the lift down to meet him. Follow him into the computer room and grab Michael Abram’s PDA off the desk. You can also get extra ammo from the glass case in this room, press the button on the blue screen to open it.

When you’re done leave the room and go right into the chamber where the scientist was trapped. Go straight through the next door and turn right, there’s a maggot and some z-secs on the walkway above to kill. When you enter a few trites will spawn in and there’s a medkit on the right. Go up the stairs at the back of the room and shoot the exploding barrel to take out the z-secs, they’ll be followed by more trites; some of them will come from behind you.

Once it’s clear the room to your left will open revealing an imp and some pick ups. Head across the walkway and take the door on the left, it’ll lead to some pick ups and a broken door, go back and take the next door on your left, head straight through the corridor and in the next room you’ll find Henry Nelson’s PDA on the desk on your right and you’ll get instructions on how to proceed.


You have a choice of routes, a more dangerous one which is lit through the EFR system or a safer dark option across the service bridge. If you head down the ladder on your right you’ll find some pick ups and two imps will spawn in. Heading round to the right another five imps will spawn in and you’ll find loads of pick ups in an alcove.

Head back up the ladder and hit the bottom option to activate the bridge, a couple of z-secs will come in through the door behind you. Cross the bridge and take out the two imps that spawn in to your left and the trites. Cross the next section of bridge to your right and kill the z-sec that comes through the door at the end and any more trites that turn up. There’s a medkit in front of the crates.

Turn left go through the door and kill the three z-secs inside. You’ll find pick ups on the shelves in this room but watch out for an imp sneaking up behind you. Head through the next door and cross the bridge being careful to jump over the gap at the end. Grab the armor off the desk as another imp spawns in to your left. Take the ladder up, go right and take out the maggots and trites that spawn in. There will be another imp towards the end of the corridor then you can turn right and climb down the ladder and grab the armor.

EFR Substation 3

Walk across the next bridge and into the room, kill the maggot that spawns in and the trite then climb the ladder. Use the code 651 to open the cabinet then go through the door, across the bridge and through the next door. Some trites will turn up as you go down the stairs. Check under the stairs at the bottom for more pick ups and then go through the door.

Kill the z-secs across the bridge and walk over. Turn right and head up the stairs and through the door watching out for more z-secs. Go through the next door and you’ll see a large chamber through the glass, proceed through the next door. Watch out for an imp lunging at you out of the darkness on your right.

Head down the stairs and you’ll find a medical station and some armor. Go through the unlocked door and you will trigger a cut scene. It’s a vagary! Use the chain gun or grenades to take him out, watch out for the wreckage which he will levitate and fire at you. When he is dead enter the air lock and you’re done with this level.

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