Turn around and exit the room. You're making a sprint in that direction until you enter a hallway. Take a right and then your first left and follow Bella until you see a door blow off from the left side. When it does, run through where the door was and up the stairs in the auditorium. Open the door at the top and look into the new hallway on the right side. You'll see a canister in the door. Shoot it so the door will close.
With the door closed, you can now proceed to the left. Follow your partners through the hallways and into a room with large windows. Eventually they'll open a door to your right and you can go through. Turn left here and go through the door at the end to find an [Incinerator Unit]. Now head back into the hallway and through the other door in the hallway to find some enemy soldiers (about 8).
Turn right and you'll see enemies scattered across the entire room. Fight them off but as you are doing so, they will try and make their way to a door on the left. When they've all left or been killed, follow O'Neal into a locker room at the end of this room for some [Armor]. Exit the locker room and turn right to find [Health] and then continue to follow O'Neal in this hallway.
Open the door at the end and protect Bella from the few enemy soldiers in the hallway while she opens the door to the left. This door, when open, will lead you into another room with more soldiers. Pop in and out of cover to kill them quickly and then move through the room. From this room, you should be able to get into the other side of the previous hallway where you'll find some more [Armor].
Across from the room you just left will be another room. Shoot into the room to clear the two soldiers just inside and then enter. Sweep around the right to take out a few more soldiers before making your way through to the left side of the room. A couple more enemies may still be alive. Exit the room into the dark hallway and follow this to catch up with Bella and O'Neal.
The Lower Levels
O'Neal will cut through a doorway and you'll enter an elevator that will eventually lead to a lower level. When you get off, go through the door to the left and follow O'Neal who will undoubtedly pass you. In the next room, behind a large console will be some [Ammo] and [Armor]. Follow your squad until it leads you to a sealed door. There's plenty of [gear] around so grab it before torching the door.
When the door has been cut open, clear the door and let your team enter the room. You will be on an upper catwalk above some water. There will be multiple Aliens and Soldiers in this room but if you hang back, you should be able to shoot most of them from a good range while they are fighting each other. If you fall down, Aliens will come down after you but you can also find [Armor] at the back of the area. There's also an elevator down here that will lead you back up to the upper levels.
Clear this area and head through the back of the room to be lead to another winding catwalk but with a few Soldiers. This catwalk area leads to a room with a button. Hit the button and the enter the large bay area beyond. While you are in there, you'll be attacked by a group of about four Aliens. Once killed, O'Neal will lead you to a hatch and you'll drop into a sewer filled with dirty water.
Follow your squad until you need to drop down a few flights of stairs. When you reach the bottom, you'll have to meet up with your squad by a door but if you can jump to it, a higher level has [Armor]. Go through the door and in the next room will be some more [Ammo] on a computer console. GO through the door on the left and follow the left catwalk. If you fall down, there's a set of stairs that will lead you back up. You'll get attacked by a handful of Xenomorphs but if you can stick with your squad, they shouldn't be a problem.
Get through the door at the end of the catwalks and you'll find yourself in a large steamy room with a couple Xenomorphs. Shoot down the hall through the steam and you should could them quite easily. Go to the end of the hallway and through the door beyond. From here, you'll be trying to catch up with your squad. Run past the large windows and open the door to find a single Alien. Go through this room and then back out to a room with large windows again.
In this second room there will be about six aliens running all over the room including on the windows. There's plenty of space here though so hang back, let your squad draw the attacks and you'll be free to fight from a distance. Go forward, through a door on the left and then back through another door on the right for yet MORE WINDOWS. This time, however, the bay will be losing atmosphere and will suck you forward. In the next room that you're sucked into, you'll be free to move around again.
In this large back, check the back right of the room to find more [Armor]. Wait for the elevator to come down on the left side of the room and then climb up. Go up the elevator and on the upper level, go through the door to enter a Hangar/Cargo Bay.
In this room, there will be quite a few enemy soldiers. Get behind the ship and there's plenty of [Armor] and [Health]. There will be a few releases on the upper levels that you need to activate so that the ship can get free. Get to the control room to start the process and then activate the releases on either side of the walkway (right side first). When both have been activated, clear out the remaining soldiers and head for the ramp but be careful of the new Xenomorphs that have joined the fight.
