Steam, Tracks, Trouble & Riddles (S.T.T.&R.) is a single player adventure mod, based on source engine (Orange Box) by Valve. It combines two types of game play: an adventure game with complex, 3D-interactive riddles in a fantastic environment and a simulator for track based vehicles.
Have a look what's better to be avoided in the renewed "Chapter One V2" to solve the puzzle at this point. Hear some new lines with the voice of Ross Scott recorded for this new version.