Penumbra: Requiem/Power Station

The ball
You wake up, looking at a funny looking ball. It is in an electrical field, preventing you from touching it safely. Find a crate, and throw it at the ball to dislodge it.

Roll the ball along the floor, and down the corridor. If it touches the lasers, it will be returned to the original room. While it seems to be impassible, there is a route - roll the ball on the left and up the side of the corridor. Move it to the other side when possible, and repeat pushing it on the side ramp.

The end of the corridor is a small loading tube for the ball. This transports it to the main section outside.

The pipe
While crossing the bridge, the mysterious ball will appear at the top of the tube, and slowly roll down. It's final destination is the pit at the bottom, but you need to unblock a few passages first.

Cross the bridge and head to the other side. First, enter the left building, jumping across the moving platforms to the opening.

In this building, you need to reach the switch above. First, move the large crate into position below the one that's raised in the air. Next, use the controls on the walls, which should allow you to build makeshift stairs to the ladder above. You can now pull the switch and let the ball continue. Also, collect the strange globe at the far end of the platform if you haven't already.

Head to the left building, and enter it. The ball will stop at three gates, which are raised by the control panel. start with the leftmost switch, followed by the center then right switch. Wait a few seconds between the switches to ensure that the gates remain open long enough.

Before heading to the bottom, you need to retrieve the second strange globe. Look for a ladder leading to the half-pipe, and walk to the to collect the globe.

Next, return to the midpoitn of the pipe, and jump onto the beam above the three moving platforms. Climb across the scaffolding and platforms to reach the lower half of the transport tube and the bottom.

Electrical system
The bottom of the map is covered with water, which is lethal to the touch. The only way to reach the lowest section is to use the transport tube.

Climb in, and move the metal plates to create a ramp for the ball. Push the ball into the middle, and touch it against the electrical tubes. When all four tubes are destroyed, you can collect the final globe. A 5 minute timer will start, and all moving platforms will freeze in place.

Before heading to the portal, walk along the rim of the lower section to retrieve the strange artefact.

Return to the portal. It is located across from the three moving platforms.