Penumbra Overture -

Essential for navigating the dark tunnels of Shaft 13. Notebook: Used to record the code once you've revealed it.

Found in the tool shed; needed to release the minecart in Shaft 12. Penumbra Overture

Detailed walkthroughs for these sections are available on GameFAQs and the Penumbra Wiki . Essential for navigating the dark tunnels of Shaft 13

Inside the office/storage room, there is a switch on the wall that turns on a purple UV light. Penumbra Overture

Are you having trouble finding the or navigating the spider tunnels to get to the lockers? Penumbra Overture | The Blank Paper | #10