Red Section soldier 1: "This should allow us plenty of time to clear out before all hell breaks loose."
Red Section soldier 2: "Are you sure that's enough time?"
Red Section soldier 1: "Yeah, I'm sure... We still have a target loose here. We have to make sure he can't deactivate this thing once we leave."
Red Section soldier 2: "Who the hell is that up there?"
Red Section soldier 1: "It's him, you idiot!... Send backup to the pump station! NOW!"
You will now switch back to Gabe for the rest of this episode. Wait for a few seconds as the thug in front of you goes to his post and then enter this area. Use your knife on the first enemy and shoot the wall mine to burn the second. This will trigger a valve, so turn the switch off. It is recommended that you keep your EDSU goggles turned on for 99% of this mission to avoid a nasty death by mines.
Entering the next area, you will find a wall mine. Diffuse it or shoot it - it's your call. Go towards the smashed window and exit the room. This will trigger a squad of enemies, including a few snipers. Kill the rooftop men, and then drop the others. You can always snipe the wall mines to use them against the enemies.
Enter the next giant window, and drop the lone wolf here. Silently head down the stairs and you'll find another mindless thug checking a wall mine (One wonders why such lack-of-brains soldiers would be out in the field). Regardless, punish him for being such a moron with a few well-placed shots to the explosive. This will again cause a valve to blast flames. Switch it off, and reload your weapons with the box of ammunition. Enter the ventilation shaft and you'll encounter a soldier blocked by a rotating fan. A few precision shots will kill him. Shoot the green light and head through the vent.
Brace yourself for a challenge. There are seemingly infinite enemies and a ticking clock. Once the timer hits 0:00, the bomb will detonate. Kill the two who come after you. Turn your EDSU goggles on to detect laser mines. Sprint down the hall and look on the other side, then down all the way - you should see a mine. It's best to destroy it. Use the RTL and when you get half way look down. There's a mine on the pillar which you need to shoot. Quickly cross to the other side and drop the 3 thugs who attack. Go to the end and slide down the ladder to trigger 2 more foes; kill them. Head to the end and slide down the next ladder. Another contingent will assault you so kill them quickly with the shotgun (if you still have it).
Breath a sigh of relief as you climb up the ladder and switch off the explosive.
1: In the large area which has crates in the open, climb onto one of those boxes and search it. It's the large pile of crates, the easternmost crate in the pile.
2: When you're inside the vent which has an enemy and a switch on the other side, go down the shaft to find the next file.
3: On the first level of the bomb room, there are some crates in the back, and if you hang off the edge to move behind those boxes, the third file is there.