1. Fight your way along the corridors and down these stairs.
2. Through a door on the left you'll find this armor and large medkit.
3. Return upstairs and fight your way down the stairs seen here on the right. The prisoners you just freed will also attack you -- go figure.
4. Drop through this opening.
5. A battle rages above between the guards and the prisoners. Continue through here.
6. Guards fall down this shaft. Climb the ladder far-right.
7. Climb the bars to the ladder upper-left.
8. Hold position here and lure the enemy into your crosshairs.
9. Fire on these two gun turrets while their firing sequence is winding down.
10. Head left to these two large medkits. Descend the ramp ahead.
11. Note the health and ammo on the left.
12. Fight your way farther down the stairs.
13. Destroy these turrets whenever you can get a clear shot.
14. Keep an eye out for newly-spawned enemies above.
15. You'll find a medkit in this crate under the stairs.
16. Another medkit can be found here. Continue through a door behind those stairs ahead.
17. Head through this door.
18. Drop below.
19. Drop through here.
20. Approach this passage to load the next area.