1. Ready your wrench as you search the side rooms -- a Hybrid patrols the area. Through the door on the left, then through a second door, you'll find a Korenchikin audio log plus six standard bullets. Through the door on the right you'll find a replicator, and there's a broken grenade launcher behind the counter. Six rifled slugs are found behind the last door on the left. Continue through the door at the end of the hallway.
2. Before heading for the upgrade stations on the left, enter the room on the right.
3. Listen to this audio log from Turnbull to learn that the security code for sub armory (the door ahead) can be found on deck four.
4. Return to the hallway and approach this OS Upgrade unit. Choose the upgrade carefully -- you'll only get four chances at this. Here, I choose Security Expert, giving me +2 hacking skill on security computers. (A security computer can be found just inside the room on the right if you'd like to practice.) The science bulkhead seen on the left will return you to Xerxes.
5. Across the hall are the upgrade units, two downstairs and two more up the ramp on the right. A replicator is also found on the level above.
6. I have 17 modules. Here, I spend 15 to upgrade Psi from 3 to 4.
7. I recommend disabling the security system before continuing down this hallway. Either way, you'll hear Xerxes identify you as a threat.
8. You'll find this security camera at the far end of the hallway on the left. Take it out early so you don't have to worry about it.
9. You'll also do yourself a favor by taking out the two hybrids immediately. You'll find a pipe hybrid as well as a more lethal shotgun hybrid.
10. Through the second door on the right is this room. Hack the computer on the right to lower the force field on the left. You'll find a medkit, armor - and a security camera inside. Three proximity grenades are in the desk ahead, and if you have hack level 2 or greater you'll find an anti-radiation hypo in the security crate.
11. Descend the ramp to the flooded hallway below. Six standard bullets are found on this corpse. Through the door on the left is an audio log from Suarez, and a Psionic Amplifier is found in a desk.
12. Behind (1) is a creepy audio log from Polito. Inside the garbage can at (2) is a BrawnBoost implant. Find ten nanites on a body at (3) before throwing the light switch at (4) and entering the room.
13. Climb the ladder at (1). Find four cyber modules on the corpse at (2). Jump or use psi-pull to grab the 20 nanites at (3).
14. Find Dr. Watts' office across the hall.
15. Watts isn't here, but Polito tells you he's probably in his office in the R&D sector. Find an R&D Access Card in this desk and Polito rewards you with five cyber modules.
16. Just outside of Watts' office, look up and to the left. There's a nanite container on one of the pipes. Use psi-pull to get the 20 nanites.
17. Backtrack to the Science bulkhead, but don't forget the upgrade units across the hall first. Here I upgrade Hack to level 2.
18. Next, I earn my first tier two Psionics skill - Adrenaline Overproduction.
19. Adrenaline Overproduction allows me to take down pipe hybrids with a single swipe of my wrench. I heard this one milling about nearby and had to try it out.
20. Pass through the Science bulkhead then keep right and pass through the door facing Xerxes' face to return to the elevator, seen here on the right. Continue down the corridor on the left.
21. Take out this security camera.
22. Be prepared to do battle before entering the room on the left, where you'll find a hybrid and a monkey. Search a desk for a Grassi audio log, another desk for three anti-toxin hypos, and a security crate holds 11 nanites plus anti-radiation and medical hypos. A second hybrid patrols the adjacent rooms so be prepared for him as well. Continue through the door at the end of the hallway.
23. A medical hypo can be found in the body bag to the right. A second hypo is available through the door on the left, underneath debris in the corner. A hybrid patrols the lower level ahead.
24. If you shoot the explosive barrels you'll take out the hybrid in spectacular fashion. Twenty nanites are in the trash. Another 44 are found in the security crate.
25. Before using your R&D access card on the door ahead, grab Delacroix's audio log from the gurney on the left. Note the replicator on the right.
26. Receive four cyber modules. Take out the security camera ahead. Continue through the door on the right.
27. Polito tells you that Dr. Watts is in his office. Pause to watch the ghost on the left before entering the room on the right. Inside you'll find a disposable maintenance tool on a corpse, an energy recharging station, a box of 6 anti-personnel shotgun shells and an audio log from Diego. Grab a speed booster off the body seen far-left before continuing around the corridor.
28. A shotgun can be found on a corpse beyond this door. Ready your weapon of choice before continuing around the corner ahead.
29. Take out this camera. Turn around and find six standard bullets on the ledge behind you before entering Dr. Watts' office seen left.
30. Defeat this solitary hybrid below with the power of your mind.
31. Find six armor-piercing bullets and a pistol in this left corner.
32. Approach the unenhanced (and dying) Dr. Watts. Grab two audio logs off him. The first reveals the code to the maintenance shaft 12451. The other audio log is as scary as anything in Doom 3.
33. Two shotgun hybrids attack. Take them out then heal at the surgical unit.
34. Find a med hypo here before backtracking to the maintenance shaft.
35. Be ready to do battle with this robot as you round the final bend. Search its remains for loot after you've defeated it. I found 20 nanites and a disposable maintenance tool.
36. Enter code 12451 into the keypad and receive six cyber modules.
37. Find a maintenance tool on this corpse before descending the ladder to engineering.