This fan film is called Aperture: Lab Ratt and made by Synthetic PictureHaus. It is based on the Valve comic called Lab Rat. Lab Rat told the story of an Aperture scientist named Doug Rattman, who apparently was one of the only survivors after GLaDOS's take over. Rattman was responsible for placing Chell (heroine of Portal) at the top of the list of test subject candidates that GLaDOS was to use and he also provided clues and warnings "behind the walls" of the Test Chambers for Chell to follow. Truly an important man whose story had to be told.