Portal Reloaded is a free, community made modification for Portal 2. The mod builds on the concepts of the main game, by allowing you to place a third portal, which enables traveling between two different timelines. Thinking in four dimensions is vital to solving 25 brand new mind and time-bending puzzles.

You play as test subject [4-5-0-9]. Awoken from stasis by an automated AI, you are expected to perform a very special test course. Within the depths of Aperture Science, secluded from the rest of the facility, lies a previously unknown and long forgotten testing track.