Kudos to everyone who has posted so far. I really enjoy reading this kind of stuff. To all those who say that this game lacks story, I answer with "You never played Dark Souls". In that game, the story was intentionally ambiguous. I've also heard people compare it to Half Life 2, but I never played that so I can't really speak to it. I digress. My point is: the story is up to you. How much effort do you put forth into finding the ghost fragments? How much do you pay attention when you're exploring? How much time do you spend thinking about the game, even when you can't play the game? All of this determines how much story there is, and if you ask me there's a metric -blam!- TON. I submit that the darkness represents the natural order of the universe. The traveler is an anomaly created outside of time. It's an invader from a different universe/dimension. I believe the Fallen were the original witness to the invasion and they are the only group who know the Traveler for what it is: an engine of change sent here to use our dimension as it saw fit. The darkness is our galaxy's "immune system". The traveler shows up, infects a solar system, and the galaxy restores balance by extinguishing all marked by the traveler. Some factions of fallen society thought the traveler was a god and welcomed the "blessing". Others were not so sure, and they stayed "pure". Divisions started forming in their society, and a war began. Before the newly blessed fallen could crush the pure born, the darkness came and swallowed up the blessed society. With no lifeforms to manipulate, the traveler moved on. The fallen saw this happening and vowed to stop the traveler and all it. The traveler is searching for something. Sent here to find a weapon that will save them. The Exo race (and therefore the stranger) is likely from this universe, as are the Vex. I believe they are engaged in a war for total domination of their universe and the losing side needed to tip the scales in their favor. Thus, the traveler was sent to create a weapon. The vex eventually discovered this alternate universe, and began the same process of using our planets and resources, for their war with the Exo... or maybe the Awoken. Not sure on that one yet. SO... that's what I've theorized so far... what do you guys think?