Based on a real place, this mod for the Source engine is played on an abandoned industrial complex & school, and some other places i might add.
Explore it freely, with a loose story.
This mod requires "Source SDK Base 2013 Singleplayer". It is extremely optimized to monitors with 16:9.
Remember, this mod is mostly about exploring, so don’t get stuck in an elevator for five minutes if you don’t know what to do, explore the areas for solutions to progress the game.
There are a lot of details, so do check every cranny! Though, not everything has a point.
The gas can be turned off. You’ll know what it means when you get there.