Grimoire Cards.

Some people tend to think the story is lacking something, but those people haven't read the Grimoire cards. I've been reading and have gotten possible hints that the Vex might be human and the reason we had guns on Mars is because we detected something that was affecting our Solar system there. Also it may be possible that the light of the Traveler exist not just in the here and now, but through out all time. And hints abound about the Traveler being linked to the Darkness. So to be honest I'm excited to learn more! The Grimoire cards are so much more than just info stamps about the enemies we face, they seem to be a vital part of the Lore.