A few years ago I discovered, when you (SPOILER)re-enter Midgar, in the Sector 8 slums, after you enter the tunnel with the train tracks, if you got all the way back to the 'start' of the tunnel, there is a door. If you try to enter this door, Shinra soldiers come running out, and you have to fight them. I did this over and over for about two hours, before I gave up, does anyone know what this door is?