1. Step forward to chase the Keeper away.
2. Listen to Elouit's request to save the portal.
3. Ready your acid-spewing shotgun before these hunters burst through the door.
4. Step through the doorway then fight your way to another doorway where this hound attacks.
5. More hunters spawn as you charge through the corridor. This is a nice sequence for shooter fans.
6. Pass through a mouth door then drop to the level below.
7. More hunters are waiting to be hunted. Use your rifle to save your big guns for the upcoming Centurion battle.
8. Two Centurions attack in succession. Lightning and Auto Cannon rounds make relatively short work of these guys.
9. Grenades are especially effective against these lumbering beasts.
10. Health spores are scattered throughout the room and two weapons lockers are in the back.
11. After both Centurions are defeated, this harvester snatches Jen away. Listen to Mother then gather as much health and ammo as you can before following through the portal.