Civil Protection Unit 3650, otherwise known as Aiden Walker, was assigned to an offsite team following an incident involving multiple other CP units. It is from here that the story of the original Entropy: Zero begins. After the events of Entropy: Zero, Aiden Walker is brought back to life as an Overwatch Elite. His will and faculties were restored, as he was supposedly the last of his copies. His directive is to capture Judith Mossman and discover what she is looking for. While City 17 and the surrounding coastal area serves as the visual setting for Half Life 2, Entropy: Zero 2 takes place primarily in the vast frozen tundras and mountain ranges where the Borealis was teased to be located. In fact, the video for Episode 5 shows the letter “B” for about a second and matches with the name “BOREALIS” found on the hull of a cargo ship supposedly carrying it. The mod features three endings and one secret ending, each resulting from the player's decisions throughout the final chapter of the game.