A MATTER OF TIME | Thinking With Time Machine #3
Very important message in the beginning! If anything, just watch it the first three minutes.
This is the pretty interesting conclusion of one of the greatest Portal 2 mods to come around in a while. It gets more mind-bending than ever, bonus: it includes me raging of the Portal 2 executable crashing on me. Double Bonus: It seems as if Ellen McLain (GLaDOS) makes a short cameo appearance.
The mod is available for free on Steam.