I've been waiting for this particular episode to come up for a few months & it's not what I expected. Apparently scattered in our lore, there are indications that our traveler had ulterior motives for coming into our system that we've never dared to wonder about. Are we simply dead things given a purpose that is only to make other things dead? In the Paradox mission's secret ending, praedyth tells us the vex have seen their future & in it they get destroyed. Are we the ones who end up killing them? Aren't the vex simply there to alter time as they see fit? I don't know much about lore but I'm going to start exploring it much more so feel free to comment & share what you know. Edit: I have read the book of sorrows but it simply doesn't fill in all the gaps & consequently doesn't "kill" this theory. According to the book, Crota was sent to our system after the Traveler so if you choose to believe the book is the explanation everything then why are the hive not in any place of power on earth? If no considerable figure of power for the hive was on earth then the hive had nothing to do with the Traveler's current state. At least some if not most of the grimroire was created for the initial story of destiny which is very different from the one the game actually shipped with so some of it just won't coincide with the current story.