1. This the most extraordinary chapter of this outstanding game. When the chapter begins, the cave entrance has collapsed. From the radio dialogue between Nomad and the VTOL pilot you learn that the only way out is through the alien structure.
2. There are some weapons ahead. Pack up. You'll need all the ammo you can carry.
3. Pistols can be found a few steps ahead, and an FY71 rifle is up the stairs. You'll have to choose two among FY71, SMG and shotgun. Shotgun is a must have. Whatever you choose, get full ammo.
4. Take the stairs to the upper platform. Your map and radar show nothing but static, but the lights here leave no doubt about the way to go.
5. This is going to be a memorable journey. Break the grate by punching, shooting or melee attack with your gun and walk in.
6. The world inside is like an alien planet. A creepy, dark, cold planet. The VTOL pilot will tell you that he lost your video signal. Well, it wasn't any better when he had the signal.
7. You'll notice that the compass is swinging wildly, rendering it useless. Hoping his buddies can see the unbelievable environment, Nomad boosts his video feed.
8. Its fun to smash these ice crystals. Better not waste your bullets on them, though.
9. Move past the crystals to this circular opening. It will open when you get close to it. Walk in and get across.
10. In the next chamber, walk ahead and look up. You'll see what seems like an alien assembly line shaped like a cylinder above you.
11. You can see an Alien Scout, the same type of alien life form that snatched your friends earlier, getting recharged and repaired.
12. Soon some type of cold gas will fill the room and you'll start floating around, as if the place has no gravity.
13. With no gravity, you'll feel like you are in space. Luckily your Nanosuit has thrusters so that you can control your movement. Use movement keys as usual to move forward, backward, left and right. Press the 'crouch' key to go down and jump key to go up.
14. This may take some getting used to so float around the area for a while. It's easy to get disoriented in this environment. When this happens, locate something obvious and move to it. This will help to regain the sense of direction. Luckily the thrusters will keep you upright even if you go upside down.
15. When you are ready to leave, come to ground level and look for this hole with sparks around it. It will be to your right if you face the far end of the assembly line.
16. The hole takes you to a tunnel. Midway through the tunnel, something will smash the grate to your right from the other side with a startling groan. Go through the grate.
17. The background music sets the mood to match the dark and creepy environment as you move to a rock tunnel with ice crystals on all sides. Proceed through the tunnel.