I have spent alot of time reading grimoire cards and trying to piece things together and I have came up with a strong theory on how to unlock secret areas in the vault of glass and possibly chests as well... If there is any. If anyone is still interested in hearing my theory just comment back. I don't want to type this all out if no one is interested haha. If I get comments I will edit with my theory as well as facts to back it up, I have yet to try it but am in the process of doing so... [spoiler]after reading through grimoire cards I was reminded that the card for the gate lord as well as in the story they say "Warlock scholars believe that Gate Lords regulate traffic between Vex gates, and that their minds contain codes that might open the way into forbidden realms." Then another day I realized that in your inventory we have 10 mission item slots, and never really use more than 1 or 2 at a time. So my thought was that maybe in order to open secret areas of the vault or any raid we need to start a new character and keep as many mission items as we can get without turning them in, then use bounties to level up to 20. So that way we can enter the vault with the eye of the gate lord as well as other items and use them to open certain areas. Example maybe eye of the gate lord is meant for the dead gate before atheon. Which could mean that each mission item could essentially open its own area or used in combination. i have not yet tried this but once I work up the courage to delete my 3rd character and start a new I will try this. Let me know if you think I'm onto something or not[/spoiler]