Part 17

On the mid-section, move to the wallwalk connected to this section and follow it up into the next area.

Grab the Crawler Launcher from the table straight ahead. Its secondary function creates a temporary shield that blocks projectiles.

Turn around, follow the path to your right, and kill the hunters.

When you reach the wall, shoot the gravity panel on the ceiling above it to switch gravity and pass over it.

Pass the next wall in the same fashion.

Use the alien hand on the panel to open the door at the end of the hall.

Wait until the large object is retracted so you can cross the metal grid to the other side.

Jump through the window into the small room, kill the harvester, and use the touch screen monitor.

Step outside and kill the flying harvesters with your new launcher.

Wait until the second large object is retracted, then hop over to the other side.

Kill the hunters and use the touch screen monitor mounted on the railing at the end of the walkway.

Wait until the moving object retracts, then hop onto the middle grid on the front.

Ride the object and jump off just as you get close to the platform to your right.

Wait until the beam of energy stops, then quickly jump into the tube, turn left, and start running.

Take an immediate right, kill the harvester, and move through the door at the end of the area.

Enter your spirit form and cross the visible bridge over the gap.

Head into the other room, press the switch to retract the bars.

Return to your body, backtrack to the previous room, and go through the door past the newly retracted bars.

Clear out the harvester and flying enemy, then hop down to the area below.

Climb up the two metal platforms at the opposite end.

Locate the explosive ball and push it towards the door covered with strange material.

Step back, shoot the ball to release the door.

Go through the door, follow the hall, and step through the blue portal.

Use the alien hand to open the door at the end of the hall.

As soon as the door opens, take out your rifle and snipe the hunters.

At the end of this long, narrow area, drop down on the pipes and follow them to another area.

Take the wallwalk to the left into the next area.

Hit the switch to disable the eye stalks, then proceed through the door.

Kill the hounds and hunters, and follow the walkway around until you reach the end.

Hop down the two platforms, wait until the cube is finished being built, then fall down the hole.

To solve the cube puzzle: Stand on the gravity switch and face the gravity switch the arm is pointing towards. Shoot the gravity switch on the wall ahead. Repeat this process until the small blue cube fills the gaps and reaches the second arm.

When the cube puzzle is complete, it will detach. Follow the wallwalk across from you until it ends.

Cross the pipes again to reach the platform with the spinning object. Step into it to be pushed to the upper level.

Kill the harvesters and the flying one.

Step through the orange portal that opens at the end of one of the catwalks.

Stand on the first half of the catwalk, spirit walk to the switch on the railing, and press it.

Return to your body; the catwalks will connect. Move to the second half and let it carry you over.

Go through the door, spirit walk through the forcefield, and use the switch to your left.

Return to your body and pass over the forcefield.

Move to the very end of the room, hugging the wall near the arrow pointing up.

When the gravity switches back, guide yourself into the opening in the wall. Alternatively, push giant blocks past the forcefield while gravity is switched, then push them together below the opening to hop up.

Go through the opening to the next area.