(1) You don't get much of a break as you start this second section of the game--as soon as you open the entrance door, a company soldier marches up and starts shooting at you! Pulse rifle him and move down the stairs to the main corridor of this level.
(2) Turn left and lob a seismic charge at the first wall recess to your left. This opens a secret U-shaped hallway with 10 derm patches and a single shotshell inside. Just past the shotshell is another secret wall with a pulse rifle behind it. Once you've collected these goods and turned around, a new enemy will be lying in wait for you before you can make it back to the main hallway: 3 young dog aliens have materialized in the U-shaped corridor! Utilize the pulse rifle to clear the way; another company soldier may be waiting for you just as you exit this secret.
(3) Now continue to your left down the primary hallway until you are near the end (you wax another soldier here) and open the right door. This large room has a divider in the middle. You will encounter 4 young dogs inside upon first entering, and another 4 will appear in the near (door) half of the room as soon as you start grabbing powerups in the far half beyond the divider. Don't leave without finding all 9 derm patches and the auto-map lying around on the desks, beds, and floor. There are also 2 med kits within, 1 each on the 2 beds farthest from the door.
(4) Upon exiting, open the doorway opposite you (right in front of you across the hallway). Kill the young dog alien that comes running up the stairs as soon as you enter, then move all the way down and off the stairs to greet a second young dog with an identical welcome (you'll pick up a derm patch en route). Now throw the single switch in the room to turn on the lights. You now have 6 cryotubes to open. The 2 in the center of the room contain a chestburster and ID tag, respectively, as you move away from the switch. The 4 cryotubes against the wall, moving away from the switch, contain nothing, a chestburster, an ID tag, and another 'burster.
(5) Now exit this room and immediately turn left to face the apparent end of the corridor. Behind the wall is a secret room which, when blown, reveals 3 facehuggers, 2 seismic charges, and a shotgun.
(6) Now do an about-face and start heading toward the other end of the corridor. Enter the only hall to the left that you will encounter and kill the young dog waiting about halfway down. Move forward and down the stairs; you are now entering a large, octagonal room housing the crashed EEV. You will be fired upon as soon as you enter by 4 soldiers; killing each yields a seismic charge, grenade (this powerup only gives you 3, though), or 9mm pistol.
(7) You can now enter the EEV undisturbed. Within are 3 facehuggers (1 or 2 may have already exited and attacked you, depending on how close you got to the EEV while killing the soldiers). There are also 3 cryotubes (the middle one holds an ID tag while the other 2 hide chestbursters), and 200-point body armor--a definite sight for sore eyes. Soon after entering the EEV, a new company soldier appears outside and walks up to the doorway to shoot at you.
(8) After killing him, you are now ready to deal with all the crates in the room. Just behind the stairs you came down are 4 crates; one holds a med kit. Working clockwise from there, you will find: a stack of crates on a lift (don't blow these just yet); a pile of crates in a wall recess (holding 2 facehuggers and a pair of night vision goggles); a small cluster of crates (housing a single 'hugger and the battery you will need to open the exit door); a large stack of crates in another wall recess (contents: 5 facehuggers, a clip, and a second 200-point body armor suit! But watch out--a young dog is hiding behind these crates); and, finally, a stack of crates sitting on a second lift (don't touch these yet!). There are a lot of facehuggers to deal with here; be very careful not to let any get away up the stairs and into the main hallway, or you will be reviving a LOT of enemies as you try to follow and kill the wayward 'huggers! The long-reaching pulse rifle is the weapon of choice for nailing the critters before they can make good their escape, but be especially cautious not to prematurely open other 'hugger-holding crates in the process.
(9) Now go back to the crates on the first lift and, making sure you are standing on the lift, shoot them all open to make the lift rise. At the top you are faced with another stack of crates. Shooting these releases 2 facehuggers and reveals a pair of young dog aliens behind. Be careful--due to the close quarters, it is very easy to get facehugged. Stick with the flame thrower to up your odds of surviving. It is also easy to accidentally drop off the lift, especially if you are using the hard-kicking shotgun. When the smoke clears, you will find that the crates also yielded 5 shotshells and a shotgun. Activate the switch (although it doesn't do anything as far as I can tell) and drop off the lift.
(10) Now head to the other lift and employ the same method to activate it--you'll be rewarded with a pair of derm patches. Here, however, you may have to quickly step off and back onto the lift once the crates are gone to get it moving. Be slow and you may get left behind! At the top of this lift is a short hall; walk down it and blow the secret wall at its end to unleash 3 young dogs. After killing them you can grab the flame thrower and blow another secret wall which will let you out into the main corridor of this level. There may be a soldier or 2 waiting for you.
(11) Once you are in the hall, head left and take an immediate right into a recess with a door at the end. Open the door, enter, and kill 2 young dogs inside.
(12) Now face the door within this room (right in front of you when you first entered) and fire away at it with the pulse rifle. The words "Door powered up" will appear; keep firing and the door will slide up shortly. Inside is a pair of acid boots. Go back into the main room and find the lockers. The right locker in the row of 3 holds night vision goggles, and the middle locker in the row of 5 houses a 'hugger. There are also 5 "shootable" shower stalls here; 2 hide huggers (the cleanest ones you'll ever see!) and the rest are empty.
(13) Now exit this room and stay to your right. Kill the soldier you will meet shortly. You will arrive at the end of the hall and the exit doorway. But wait--there's more! Before activating the battery-operated switch and exiting, launch a seismic charge at the wall to your right, between the spools of wire. Inside this secret are a lot of barrels, 2 facehuggers, a seismic charge, a grenade, a clip, and an adrenaline burst. Blow up the barrels quick to kill the 'huggers and move in to grab the goods. If you've been doing well, you won't even be able to use the 200-point adrenaline burst.
(14) Now you are ready to throw the switch and exit. With an adrenaline burst and 2 body armor suits, you should be one happy camper when you leave this level!