Move forward and watch out for the bullsquid spit.
Use the lever to activate the lift below.
Use the lift to go down.
Use the tram to move forward faster. You can control the speed when you press forward, or you can go in reverse.
When you reach the end the tram will crash and will send you into a radiation pool. You can try to jump off it early.
Climb up a ladder and go inside the pipe.
Jump on the next pipes.
Jump from the pipes to the next area.
Walk on the pipes to reach the lift in the center.
Use the lift to go up.
Pass through here. Try not to shoot the explosives because they will destroy your path and will make things harder.
Use the red lever to open the door.
Pass this corridor. The scientist will tell you that you need to use the rocket engine to destroy something.
Enter the engine testing lab.
A tentacle monster grabs a scientist.
You will have to use the red button in this room to destroy the creature. But first you need to power the engine.
Go up the ladder on your left.
A guard tells you that you need to be quiet. Get the grenades that are nearby.
You will have to run past the creature to reach the lower floors. Use your grenades to make the creature hide for a few seconds.
Enter the doorway on the lowest floor. Know that all the doorways are barred and you will have to clear them on the run.
Jump over the chasm.
Open the silo door.
Move through here. If you destroy the passage you can use the cable near it to pass over.
Get through the corridor with water.
Go towards the ledge.
Call the elevator.
Don't go down with the elevator yet. Press the button to lower it and then go out. Jump on top of the elevator, this way you will have time to jump from when it crashes down into a pool of radioactive goo.
Walk on the pipe to avoid the radioactive spillage.
Use the platform.
Climb up the ladder.
Climb up the second ladder. Beware the moving platform. You have to move fast here because you can be crushed.
At the top move up the ramp and press the red button.
Get over the device. Some guy is hiding here.
On the other side you need to press a second red button. This will activate the machine.
The thing lights up. Time to get back up.
Climb the ladder on your right from where the elevator crashed.
Time to pass through the monster den again.
This time go through the doorway on the second floor.
Enter the silo.
Go down a ladder but beware the zombies waiting below.
Climb down the long ladder.
Stay on top of the pipe and go left.
Use the keypad to enter here.
You will enter the turbine room. Use the ladder to go down.
Go down one more ladder.
Press the button to activate the turbine but know that you have to climb the ladder fast to get out because the turbine will start spinning over you.
You have to jump over the windtunnel to go up. The top is barred but you can clear it with one grenade. You can destroy it with your crowbar if you don't have grenades.
The wind will push you all the way up. Climb inside a vent up there.
Destroy some boards to proceed.
Press the oxygen and fuel buttons. You will see bubbles in the pipes if both are activated successfully.
It's time to get back to the engine lab. Climb the ladder.
Use the keypad to go back.
Exit this silo.
Climb back up the ladder to reach the control station.
It's time to press the test fire button and fry the thing.
The dead creature will make a passage for you. Drop down the hole from which it came.
Before you go down in the water grab the revolver from the dead guard. It is very powerful but ammo for it is scarce.
Pass through the holes.
Swim up here.
Jump on the pipes to proceed.
There are some recharging stations nearby if you need them.
Climb on top of the pipe in front of you.
Use the valve to extend the pipe below.
The extended pipe is broken but it will help you make the jump to the other side.
Walk forward until you reach the end.
You drop down in a storage room. Destroy the crates to find some supplies.