Thread:Chaosian/@comment-3246149-20120501164919/@comment-4488593-20120501214852

It has something to due with the game's moral system. Explore, do a good deed; the screen flashes brightly, etc. If you're in any way evil, or renegade, or whatever, then a dark flash will occur with an ominous tone. This system determines if you get the good ending or the normal ending in the game.