Act 4: The Long Road Home - 5. Interior Destruction
Pull out the Lancer and wait to hear a hole open somewhere. Wait one the bottom steps and be ready for a Grenadier to pop out of the closed door. Drop back if you have to, just don't let him kill you. Run through the door with a Frag in hand and go into the right room when you see two. Get to the couch, aim a Frag as far as you can to the hole in the far room. Hope you got it, because there is another guy already shooting at you. Kill him and whoever survives, then be ready for another to burst through a door to the left.
Go through and get the ammo in the room to the right. Keep going and in the next room chainsaw the desk for COG #27.
Keep going until you reach the gate, and turn the valve. Go through, chainsaw the boards for some Frags, and keep going. Be ready to help out your trigger happy friend; you can just just stay on the top of the stairs and shoot at the enemy's feet. Go through and don't worry about the strange happenings, no fighting right now. Where you find an opening to a small room, go in and swap for the Longshot if you wish. Keep going and push the left-most wine holder back. Try to open the door, then get to the cover under the middle railings. Get ready for about six or so Drones/Grenadiers to attack from both sides, in the middle, and to rush. Then go into the lab.
Make your way back, but watch for the immediate Wretches as you try to leave. Then when you are almost out of the basement, anticipate the rush of a lone Wretch with a Grenadier behind him. Keep going until you reach the room with the desk and four pillars. A Grenadier locks you in with about nine Wretches that come from the holes in the wall. Just stay in the hallway you just came from and pick them off. When you hear the enemy laugh he should be in the room, so take him out.